MFC Dll with dialog in a new thread

Hi
I have MFC Dll with dialog, I used it in C# App.
All the function (from App to the Dll ) was at another
Thread ("Dll thread").
Not in the main (GUI) thread, but in the same one (using
queue)
The init(.) and other function first enter to Q and the
pulled by the "Dll Thread")
It's working functionality, but The MFC Dialog stays grey.
(Missing WM_PAINT (?
I think that I have problem with window handle.
The Code in the C#:
[..."MyDll.dll"...]
export static int Init(CallBack* xxx, SData* ps);
The function get delegate to return event from the DLL and
data on the application. ( name and ID, not window handle
or other data like it)
Can U help me?
Thanks
Koby