Good and interesting question... and I was wondering this too... I totally understand your question but you might not be portraying it clearly enough... probably why the other thread got confused... might also have something to do with the thread subject area...
Basically you are saying... you want to use a function which is not available in DBPro but can be made in DGDK as it incorporates I pressume C++ code and you want to know if you somehow (I say somehow because this is a battlefog area for me) export it into a DLL and use a DLL callback function inside DBPro to make use of that function
EDIT
PLACING MY EDIT INFO HERE AS THE EDITOR IS SOOO DIFFICULT TO USE ON WEBKIT
ADDED A LINE AT THE TOP REGARDING THREAD TOPIC AND CORRECTED A TYPO IN CLEARLY
ENDEDIT
hope I hit the nail on the head there
As you can see I too genuinely seek an answer to this question too
I hope someone can answer it soon... btw as I am on a mobile device... did you try a forum search for this yet?