windbg find all c++ objects of type X on heap

Question

I"m trying to find all object of type module!SomeClass in the heap. I thought a command like this would've worked:

> s -v 0 L?0xfffffff module!SomeClass

but alas, it does not. If I knew how to find the vtable address for that class, I could then search memory for references to that vtable, but I haven't had much luck finding that either. Any suggestions?