You would need to perform calculate on each selection change using the
SelectionChange event - that is about a close as you can come. You would
also need to make your UDF's volatile.

http://www.cpearson.com/excel/events.htm
For an overview of events.
--
Regards,
Tom Ogilvy


"S Isfeld" wrote:

Need to force Excel to recalculate when the user changes the font color or
fill of a cell within the worksheet. Have a custom function the counts the
number of cells with a cetain fill or font color. Function recalcutales if
the data in the range is changed but not on a chang to the font or fill
color. How can I get Excel to recalculate on a change to the cell format?