Regrouping data into text

Hi,

I'm trying to create an section of an input file that requires a specific formatting. The data is in 2 separate text files and I need to put it in one single text file with the following format:

first line=a{i,1}
second line=b{i,1}
third to +n line=d{i,1}

and repeat

first line=a{i,1}
second line=b{i,1}
third to +c line=d{i,1}

Here is the code I've been working on to try and do this but it does no work when printing to text. Any comments will be greatly appreciated. Thanks!

    if true

clear all
clc

A1=importdata('CROSS_SECTIONS1.txt');
A2=importdata('CROSS_SECTIONS2.txt');

GR=A1.textdata{:,5};

Elevation=A1.data(:,3);

Elev_Station=A1.data(:,2);

Station1=A1.data(:,1);

X1=A2.textdata{:,1};

NC=A2.textdata{:,2};

Station2=A2.data(:,1);

StationCount=A2.data(:,2);

R_bankSt=A2.data(:,3);

L_bankSt=A2.data(:,4);

n1=A2.data(:,5);

n2=A2.data(:,6);

n3=A2.data(:,7);

      A=[Station1 Elevation];
      A = sortrows(A,1);
      idx = cumsum(diff([0;A(:,1)])>0);
      idxn = histc(idx,unique(idx));
      C = mat2cell(A,idxn,size(A,2));

for i=1:length(n1)
    a{i,1}={NC n1(i) n3(i) n2(i)};
    b{i,1}={X1, Station2(i) StationCount(i) L_bankSt(i) R_bankSt(i) 0 0 0 0 0};
    d{i,:}={C{i,:}};

      fileID{i} = fopen('cross_sections.txt','a+');
      fprintf(fileID{i},'%s\n',a{i,1});
      fprintf(fileID{i},'%s\n',b{i,1});
      fprintf(fileID{i},'%s\n',d{i,1});
      fclose(fileID{i});

end

    end