randomly inserting element in 2d matrix

let there is 2 2d matrix A=[1,2;3,1] and B=[5,6;7,8] required output is C=[5,8;0,6;0,7] my code but its not that correct

for i=1:2
  for j=1:2      
      C(A(i,j),end+1)=[B(i,j)];
  end
end

is there any correct sloution where i can insert elements, in random rows of 2d matrix.

[ES]

Your question is not clear. You want to create a matrix C "randomly" with elements from A and B? Try perms, nchoosek, randperm, permute, combvec

[Jan]

I don't get it. Please explain the procedure to create the output.