It should be possible to import AutoCAD DWG drawings to older Pro/Enginer program and used it as a basis for a XPR part file.
Convert AutoCAD drawing to PTC Pro/ENGINEER part file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert dwg to xpr on Windows
Set of 3D CAD/CAM/CAE design tools from PTC
Convert from dwg file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.