Read VIEWS.HLP, it's all in there. In particular, you need to familiarize yourself with the cb command. You also need to understand what pages are and how to use them (section What is an output page?).
Just a suggestion here, why not use DCX instead? The good thing about DCX is that it comes with some examples. It is far easier and you'll have a working treeview in 10 minutes or less. It is by far the best DLL I've used.
I already have the whole thing coded with MDX, I don't wanna start coding the whole thing again... not to mention that I will code it and then descover that I can't do that I want or that I can do it with MDX....