If you can read C#, maybe this will help: https://github.com/Const-me/ComLightInterop https://github.com/Const-me/ComLightInterop Specifically, this class impl

If you can read C#, maybe this will help: https://github.com/Const-me/ComLightInterop https://github.com/Const-me/ComLightInterop Specifically, this class implementing vtable callable from C++: https://github.com/Const-me/ComLightInterop/blob/master/ComLight/ManagedObject.cs https://github.com/Const-me/ComLightInterop/blob/master/ComL... About multiple interfaces, all of them need 3 first vtable entries pointing to the 3 IUnknown methods. Also, don't forget that when client calls QueryInterface on any interface of the same object with IID_IUnknown argument, you must return same IUnknown pointer. Some parts of COM use that pointer as object's identity.