CPLEX in MATLAB - Asking for Help

Hi

I am using CPLEX in MATLAB

I want to optimize the following

min ||Y|| where ||y|| the l1 norm of y 
l1 norm of y = sum of abs(y)

S.t. A Y = 2B - A* 13n

Y is within the range of [-1,1]

for example

A= 

1  2  4  0  0  0  0  0  0
1.5  2.5  4.5  0  0  0  0  0  0
3  5  9  0  0  0  0  0  0
0  0  0  1  2  4  0  0  0
0  0  0  1.5  2.5  4.5  0  0  0
0  0  0  3  5  9  0  0  0
0  0  0  0  0  0  1  2  4
0  0  0  0  0  0  1.5  2.5  4.5
0  0  0  0  0  0  3  5  9
1  0  0  1  0  0  1  0  0
0  1  0  0  1  0  0  1  0
0  0  1  0  0  1  0  0  1

2B-A x 13n =

-5
-5.5
-11
-3
-3.5
-7
1
0.5
1
-1
-1
-1

so the value of y that solve the problem is y =

1
-1
-1
-1
1
-1
-1
-1
1

I did the above using excel solver

If I want to do it using CPLEX LP how this can be done , I want the to use the MATLAB CPLEX LP because of the huge amount of data that I have that Excel solver can't handle.

Where I reached is

[obj,x,lambda,status,colstat,it] = lp_cplex(c,A,b,l,u,le,ge,maxIter,optimizer)
[x,output]=lp_cplex(fa,Aeq,beq,lb,ub,10000,1)
fa=[1,1,1,1,1,1,1,1,1];

in order to sum the values of x ( the problem I want to some the values of |x| not x but don't know how to do that !!

lb and ub is lower and upper boundaries -1 and 1

Aeq=beq the equality constraints

Can Anyone tell me how to do the summation of the absolute value of x in MATLAB CPLEX function ?

Thank you in advance