How to skip or delete lines in text if statement

[num,mast] = xlsread('CR_Creo-Materials-MASTER - Copy for code.xlsx','Sheet1' );

baseName = [mast([14:17],4)];

name =convertCharsToStrings(baseName);
Name= name;
stringm= convertCharsToStrings(mast);
%values for input
D=num([3:end],11); %density
PR=num([3:end],13);%posidens ratio needs to be e-0x
Y=num([3:end],15); %youngs
TY=num([3:end],17); %tensile yeaild e+0x
TU=num([3:end],19); %tensile ULT e+0x
TC=num([3:end],21);%thermal concuctivity e+0x
TEX=num([3:end],23); %thermal expansion e-0x
%conversions
Y= Y*1000000; %youngs msi to psi
TY=TY*1000; %tensile yeaild e+0x KSI to PSI
TU=TU*1000; %tensile ULT e+0x ksi to psi

%sources
DS= mast([14:end],13);%density source
PS= mast([14:end],15);%Poissions source
YS= mast([14:end],17);%Youngs source
TYS= mast([14:end],19);%tensile yeild source
TUS= mast([14:end],21);%tensile ultimate source
TS= mast([14:end],23);%thermal source
CS= mast([14:end],25);%cefficient source

DS= convertCharsToStrings(DS);%density source
PS= convertCharsToStrings(PS);%Poissions source
YS= convertCharsToStrings(YS);%Youngs source
TYS= convertCharsToStrings(TYS);%tensile yeild source
TUS= convertCharsToStrings(TUS);%tensile ultimate source
TS= convertCharsToStrings(TS);%thermal source
CS= convertCharsToStrings(CS);%cefficient source
%info
MT= mast([14:end],8); %Material Type
FO= mast([14:end],9); %Form
DE= mast([14:end],10); %description
AD= mast([14:end],26); %additional info
SD= mast([14:end],28); %Source date
ST= mast([14:end],29); %source temp
DI= mast([14:end],31); %Disclaimer General
MA= mast([14:end],33); %Manufacture
GU= mast([14:end],34); %Genral use
SF= mast([14:end],36); %Special Features
AC= mast([14:end],38); %acronyms
DIS= mast([14:end],40); %Disclaimer source

MT= convertCharsToStrings(MT); %Material Type
FO= convertCharsToStrings(FO); %Form
DE= convertCharsToStrings(DE); %description
AD= convertCharsToStrings(AD); %additional info
SD= convertCharsToStrings(SD); %Source date
ST= convertCharsToStrings(ST); %source temp
DI=convertCharsToStrings(DI); %Disclaimer General
MA= convertCharsToStrings(MA); %Manufacture
GU= convertCharsToStrings(GU); %Genral use
SF= convertCharsToStrings(SF); %Special Features
AC= convertCharsToStrings(AC); %acronyms
DIS= convertCharsToStrings(DIS); %Disclaimer source

PTCCondtion =name;
PTCC = PTCCondtion;
PTCxh=PTCC;
DA= "ref_color1";%Default Appearance

numFiles = numel(baseName);
chr1=Name;
chr2='.mtl';

for k=290
for i=1:3
    % build filename % e.g. AL083Bar.txt
    filename = append(chr1(i,1),chr2);
      
     filepath = cd;
file     = fullfile(filepath, filename);
fileID= fopen(filename,'w');
if fileID==-1
  error('Cannot open file for writing: %s', file); %code to test if files broken
end
   %code for the text in the file 
formatSpec = 'ND_RelParSet_K01 = {\n\nName = %s\n\nPARAMETERS =\n{\n  Name = PTC_MATERIAL_DESCRIPTION\n  Type = String\n  Default = ''%80s''\n  Access = Full\n},\n{'
formatSpec= [formatSpec newline '  Name = TEMPERATURE\n  Type = Real\n  Default = 0.000000e+00 F\n  Access = Full\n},\n{'];
formatSpec= [formatSpec newline '  Name = PTC_BEND_TABLE\n  Type = String\n  Default = ''''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = PTC_MATERIAL_TYPE\n  Type = Integer\n  Default = 9\n  Access = Locked\n},\n{'];
formatSpec=[formatSpec newline '  Name = PTC_FAILURE_CRITERION_TYPE\n  Type = String\n  Default = ''NONE''\n  Access = Locked\n},\n{']; 
formatSpec=[formatSpec newline '  Name = PTC_FATIGUE_TYPE\n  Type = String\n  Default = ''NONE''\n  Access = Locked\n},\n{'];
formatSpec=[formatSpec newline '  Name = PTC_MATERIAL_SUB_TYPE\n  Type = String\n  Default = ''LINEAR''\n  Access = Locked\n},\n{'];
formatSpec=[formatSpec newline '  Name = PTC_POISSON_RATIO\n  Type = Real\n  Default = %7f\n  Access = Full\n},\n{'];  
formatSpec=[formatSpec newline '  Name = PTC_YOUNG_MODULUS\n  Type = Real\n  Default = %7f psi\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = PTC_THERMAL_EXPANSION_COEF\n  Type = Real\n  Default = %7f /F\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = PTC_TENSILE_YIELD_STRESS\n  Type = Real\n  Default = %7f psi\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = PTC_TENSILE_ULTIMATE_STRESS\n  Type = Real\n Default = %7f psi\n  Access = Full\n},\n{']; 
formatSpec=[formatSpec newline '  Name = PTC_MASS_DENSITY\n  Type = Real\n  Default = %7f lbm/in^3\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_TYPE\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_FORM_AND_SIZE\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MMATL_SOURCE_DENSITY\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_POISSONS_RATIO\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name =  MATL_SOURCE_YOUNGS_MODULUS\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_TENSILE_YIELD\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_TENSILE_ULTIMATE\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_THREM_COND\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_THREM_EXP\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_NOTE_ADDITIONAL\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_NOTE_TEMP\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_DISCLAIMER\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];  
formatSpec=[formatSpec newline '  Name = MATL_MANUFACTURE\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_GENERAL_USE\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SPECIAL_FEATURE\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_ACRONYMS\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_DISCLAIMER_USES\n  Type = String\n  Default = ''%s''\n  Access = Full\n},\n{'];
formatSpec=[formatSpec newline '  Name = MATL_SOURCE_DATE\n  Type = String\n  Default = ''%s''\n  Access = Full\n}\n\n}\n'];
%if D==0 %density

%%if Y=num([3:end],15); %youngs
%%if TY=num([3:end],17); %tensile yeaild e+0x
%%if TU=num([3:end],19); %tensile ULT e+0x
%if TC=num([3:end],21);%thermal concuctivity e+0x
%if TEX=num([3:end],23);

  fprintf(fileID,formatSpec,Name(i,1),DE(i,1),PR(i,1),Y(i,1),TEX(i,1),TY(i,1),TU(i,1),D(i,1),MT(i,1),FO(i,1),DS(i,1),PS(i,1),YS(i,1),TYS(i,1),TUS(i,1),TS(i,1),CS(i,1),AD(i,1),ST(i,1),DI(i,1),MA(i,1),GU(i,1),SF(i,1),AC(i,1),DIS(i,1),SD(i,1));
 % write data to file
   % writematrix(Formatspec,filename)
   
end
if PR==0;%trying to delet poisions line
    fid = fopen( filename, 'r')
    
    fgetl(fid) 
   end
end
fclose('all')

[Image Analyst]

Is this the "if" statement you're referring to:

if PR==0;%trying to delet poisions line
    fid = fopen( filename, 'r')
    
    fgetl(fid) 
end

First of all you need to accept the results of fgetl into a variable

thisLine = fgetl(fid);

Then you need to check the text line to see if it contains something you want to use and operate on, or if you want to skip doing anything with that line:

% Open the file for reading in text mode.
fileID = fopen(fullFileName, 'rt');
% Read the first line of the file.
textLine = fgetl(fileID);
lineCounter = 1;
while ischar(textLine)
    % Print out what line we're operating on.
    fprintf('%s\n', textLine);
    % Read the next line.
    textLine = fgetl(fileID);
    % Skip lines that say "skip this line" or whatever.
    if contains(textLine, 'skip this', 'IgnoreCase', true)
        continue; % Skip to end of loop.
    end
    lineCounter = lineCounter + 1;
    % If you get here then you want to do something with that line,
    % like parse it to get values out of it or something...
end
% All done reading all lines, so close the file.
fclose(fileID);