# MATLAB: Substituting a column into a 3D matrix

MATLAB

I have a matrix R = zeros(4,5,3) and I want to make the last column of each matrix a different number. such that given C is a vector
for n = 1: end R(:,end, n) = C(n)
I managed a solution where I have a column vector A which if I could substitute into R(:, end, :), but it says mismatch dimensions.
essentially, I want to substitute a column vector into the columns of a 3D matrix R without using a for loop.

R=zeros(4,5,3);A=1:20;R(:,:,3)=reshape(A,size(R,1),size(R,2))R=zeros(4,5,3);A=1:12;R(:,5,:)=reshape(A,size(R,1),size(R,3))