Well I didn't really want to use the DisplayValue because I thought there must be a way to get VFP to do it for me if I had the ControlSource set. But it looks like there isn't.

An interesting thing I found out is that if you issue a thisform.refresh() it will wipe out the DisplayValues in those controls if the control source value isn't in the rowsource. So you are forced to put the code to change the displayvalue in the refresh method of the form.