I'm working on the MFC Extension DLL which exposes the only CDialog class. That dialog is a piece of common UI that a number of other applications use. All of those applications do use BCGControlBar so it's necessary to make the dialog in DLL look like GUI of calling applications.
It's clear how to use BCG with stand-alone application (lots of examples provided), however, it's not clear how to use it with MFC Extension DLL.