How to convert a DWG to pure 3dface DWG/DXF

[D. Losch]

For compatibility reasons with older s/w I have the need to produce DXF (R12/13) solely with 3dface entities.

Since repeating structures are a drag and very time consuming, I´d rather like to copy, shift & paste than drawing each entity seperately. But AutoCAD does not copy this entity as a pure 3dface.

Is there a way (or a script) to convert a DWG with deliberately mixed entities to a DWG (or DXF) file that consists solely out of 3DFACEs ?

Cheers & Greeting from Munich