search 3D and 2D entities in .DWG file

[y2kmvr]

Hi,
Here is what I am trying to do:
I have .DWG (from mechanical desktop)files that has both 3D & 2D entities in them. I'm not able to export the complete data out of Mechanical desktop. If I use step, I am losing 2d drawing data. If I use IGES, i am losing 3d data.

I would like to (through VB ) scan all the .DWG ,if 3D entities are found, export them into STEP. If 2D entities( pure 2d drawing )are found, export them into IGES 2D.

If someone has some sample code for searching entities both in ModelSpace and PaperSpace, please post it here.

If you have some other ideas, please share with me.

Thanks in advance.
y2kmvr