>Right-click on grid, select edit, click on needed control in Controls toolbar, click on column. You may repeat this operation as many times as you want.

PMFJI, but since we're on the subject I've always wondered how you remove an unwanted control after you've added the one you want. Say you start with a text box in a column, then add a combo box. I've never been able to find a way to delete the text box. Do you know of a way to do this?