Found:
This is an example:
% Define the column 
A = [1;4;7;10;13;16]; 
% Define the value of n n = 3; 
% Initialize an empty matrix to store the new submatrices B = []; 
% Loop through the rows of the column A
for i = 1:n:size(A,1) 
% Extract every nth row of the column A 
subcol = A(i:i+n-1); 
% Convert the subcolumn to a matrix 
submat = reshape(subcol,n,1);
 % Append the submatrix to the new matrix B    
B = [B submat]; 
end

