Visual Studio 2008 Excel UDF

Does anyone know of any examples of a skeleton Excel 2007 UDF, I have searched all over, con only find one example of a COM addin with a button, none to add a UDF to Excel using visual studio.

I created a COM addin using the wizzard, but excel says it is Invalid.

Any Ideas or examples?

TIA

Daz

http://www.cpearson.com/Excel/Creati...nctionLib.aspx