Automation of C# button in Excel

Question

Hi, I have a button on excel sheet,which is construct and drive by C#. I want to automate my application in excel using VBA code which can press the button ( like set button to true ) in order to execute the C# code under it.
I use to do it with visual 2003, but i don't know if it still possible with visual 2005.
Does anyone can help me on this topic.