As I stated above, if you generate a specific question I will do the best to answer it for you. Just realize the reality is that if you do not understand it, you are going to have to put a lot of effort into reading/thinking until you do understand it, and if you are undertaking this project seriously you will develop insightful questions when you are stuck and to which I can promptly provide an answer. Ultimately, if you understand the basic idea, the code will make sense, but reading the code won't likely make the basic idea make sense.
EDIT:
Ultimately, I've just manipulated the data so that the MS3D data is turned into a new format such that it can be used with a call to OpenGL's glDrawElements. Re-reading the definition of that function on msdn.microsoft.com would be a great place to start.
