@Master Xilo,
Yeah I think you should load the ldraw .dat parts-list into your program. I got confused as to whether you were attempting to model all the lego pieces yourself. And I am still not positive exactly what you are doing. I will need to re-read your post, and demo your app again.
My first read of your post (It was late about 3:00am) I didn't know anything about Block-Cad as I always used MLCAD. After posting I went on to read about block-cad and found out that it also makes use of the standardized ldraw.dat parts-list. But I also read the limitations it had with dealing with flipping parts upside-down, rotations, and restrictions on dynamic flexible parts, like flexible axels, springs, etc...
I tought you were sort of making a lego cad like tool to build lego levels for a game. Let me re-read the entire thread, and make sure I am on the same page.