hi
not sure if i'm uderstanding correctly but if a cell is displaying #NUM!,
that is the error.
what is the fomula that is generating the error.
see this site for a explination of excel formula errors.
http://www.dummies.com/WileyCDA/Dumm...FFICESOFT.html

regards
FSt1

"LunaMoon" wrote:

Hi all,

I am using VC++ to develop some XLL file for use in Excel 2003.

Of course there are bugs.

The cell display "#NUM!".

But in VC++ I've already thrown exception with error message:

if (a!=b)
throw Constructor ("a must be equal b.", "myclass")...

Why couldn't I see the error message in Excel?

Thanks!