Help Needed

[Liam Groener]

I'm not an expert and I'm not sure how general you want the matrix A to be, but 
how about:
function B = fillit(A)
 n = (size(A))(1);
 m = n/2;
 C = A(m:n)
 R= A(m:-1:1)'
 B = toeplitz(C,R);
endfunction