In case you have Visual Studio 6 installed try using at tlbinf32.dll for information about type libraries(including vtable pos.)...
There is even help file for that dll so it shouldn't be hard to figure it out.

If you don't have it try looking at h++p://www.microsoft.com/msj/0399/comtype/comtype.aspx
In that article Matt Pietrek has provided the way of generating map file
for easier debugging of com objects...

Hope I was more helpful this time.