I want to use the Worksheet user's response to an ActiveX check box control
as a condition in a cell's formula. Specifically, if the user checks the
check box, I want to cell to display a particular character; if the check box
is left unchecked, I want the cell to test the next condition in the in the
formula. I want the cell to update if the user changes the check box from
checked back to unchecked. Can I do this in the cell's formula itself, or
will I need to use a VBA macro?

I am using Microsoft Office Excel 2003.