Add .net ActiveX to Excel worksheet
 

I want to add .net control to Excel worksheet.
So I made .net ActiveX control with reference to this URL
http://www.codeproject.com/KB/cs/Cre...veXDotNet.aspx.
It does work very well.
But I can't add to Excel worksheet.
When I have inserted the .net activex, Excel returned this message.
"Cannot insert object."

Is it impossible?
How can I add .net control to worksheet?

Thanks..