I have seen a few tutorials about creating Test Projects in Visual Studio.  The ones that demonstrate creating Unit Tests show how to generate source code and how that C# code can be used.  I would really like to know how to this with a "Web Performance Test".  So far, I have been creating test cases "filename.webtest" that is in an XML fformat and appears as a tree structure in the IDE.  How do I convert this into C# code and, most importantly, how would I call it and also use it in conjuction with other C# code?