/skins/_feedback.php is the file you'll need to edit. If you want your changes to only affect one skin, then copy that _feedback.php and replace the /skins/yourskin/_feedback.php with it, then edit that.

Thanks for the reply. Actually, I found the file I needed to edit before you replied.

FYI: editing the file directly did not change the col values unless I deleted the width attribute from the textarea style in the stylesheet.

Thanks!