The problem with c# functions and Excel is that they go through the interop
layer which is slower than molasses.

If you want to go this route and need performance then I would recommend
using a third-party product that bypasses the Interop layer and internally
uses the C API for communication between Excel and .Net.

Charles
___________________________________
The Excel Calculation Site
http://www.decisionmodels.com

"McRolin" wrote in message
...
Hello,
I've built Excel user functions with VC++6 and load them as *.xla. Can
the C## handle heavy math and build good add-ins for Excel?

Thanks,

Roger