Answer:
RFEM 6 can communicate with Autodesk Inventor in a limited way. Inventor reads and writes volumetric and geometric information similar to .IFC coordination view files. A .STEP file can be exported from this program. RFEM can then import such files under the File - Import menu options.
Alternatively, any CAD program has the ability to export .DXF files which allow RFEM 6 to read center line information. This is not a full solution and will require additional work for the user once in RFEM 6.
Lastly, a user can utilize the API II functionalities to develop a process to read any CAD software into RFEM 6 through an open API interface.
Dlubal API Service