ClassInfo, derived types, and object.Interface

[Kapps]

Anyone have any suggestions for this? Essentially trying to
figure out, given an object.Interface instance and an index
within it's vtbl property, how we can get the function pointer
for that method on a class that overrides the method. I assume
this is a better place to ask than the D.learn forum as it's more
of an ABI question than a question about learning D.