With CATIA CAD program from Dassault Systemes it should be quite possible to convert its own CATDRAWING files to 3DXML format. Should be easy enough with export or save function found in the program.
Convert CATIA drawing file to Dassault Systems Universal 3D XML document.
We found one software available in the database for this conversion.
Microsoft Windows software - convert catdrawing to 3dxml on Windows
A PLM/CAD/CAM/CAE software suite
Convert from catdrawing 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.