Conditions:
* Implement a class A inherits from IUnknown and Interface IA in a DLL.
* Implement a console application.
Questions:
* Any requirement about that DLL? Must be an MFC DLL?
* Should I register the DLL? I guess yes.
* If want to use this class, what should I do? Can I just include the he
ader file and use CoCreateInstance with interface A's id to create get a
pointer to the instance of class IA?
