Can't load xll programmatically

Question

I\'m trying to automating some tests for an Excel add-in, which is in xll form. I have some problem in loading the xll. I\'m writing it in C# and my code looks like this:

Answer 1

I know this is not a direct answer to your question, but you may want to look at using VSTO within Visual Studio. VSTO automates a lot of these types of issues. The version in VS 2010 is so much better than what they used to have and you can built application level add-ins as opposed to just document level add-ins. If you need user defined functions you can use a COM add-in as described here:

http://blogs.officezealot.com/whitechapel/archive/2005/04/10/4514.aspx

It was originally based on this article:

http://blogs.msdn.com/eric_carter/archive/2004/12/01/273127.aspx

We use a combination of VSTO for our main application, and the COM add-in for user defined functions. What's nice about that is that they are loaded in the same app domain so they can talk to each other.