There is a new SDK for 2010
the C API is still the recommended add-in technology for 2007.

If you look here you may get some ideas on issues with C# and Excel
http://www.codematic.net/Excel-devel...udio-excel.htm
(.net UDFs have poor performance)

Cheers
Simon
Blog: www.smurfonspreadsheets.net


johnlon wrote:
Incidentally Charles I was just looking on your site entirely by
cooincidence!?.
Is there a good place to ask for some advice on tracking down a perf issue
with a c# plugin for excel, that extends the available function in xl?

"Charles Williams" wrote:

It is supported by Office 2010 for both 32-bit and 64-bit Excel 2010 (with
corresponding Vista/Windows 7 versions)


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

"johnlon" wrote in message
...
Is there a published roadmap for the Excel C API.

Will it be supported in Office 2010?
What about Windows 7?

Thanks