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