indicate a change in a row

Giganews Newsgroups
Subject: indicate a change in a row
Posted by:  Picman
Date: Thu, 23 Aug 2007

I would like to indicate with a specific value ("C") in the first cell of a
row if any changes have been made in that row since the file was created. In
other words if a value was input or changed in cell "M1" i would like cell
"A1" to be populated with a "C". Can this be done?