One easy option is to do this for rows and columns separately
A = [1 2 3 ; 4 5 6 ; 7 8 9]
x = 3 ; % add a row/column of ones before this row/column
A(end+1, :) = 1 % add row add the end
A([x end], :) = A([end x], :) % swap the x-th and last row
% do the same for columns
A(:, end+1) = 1
A(:, [x end]) = A(:, [end x])
