Thank you all for the answers.

I didn't know that 3dm =|= 3dm thank you for the explanation!
Luckily I found a way to get my final project out of Modo into Moi.
I simply exported the scene as a dxf out of Modo, imported it into Allplan and from there I exported a 3dm Rhino File. :)
Moi can handle this 3dm file type and did an excellent job exporting it as an iges!
Would be cool if there will be a dxf or dwg import option in future versions.
The pdf import option is only for 2D pdf files? I tried a 3D PDF but it seems that it doesn't work.

regards