Converting .exb files directly to .dwg format.
Converting CAXA Draft files directly to AutoCAD Drawings (.exb to .dwg conversion) might be possible using the CAXA CAD software itself. It appears that it allows users to export its proprietary .exb files as .dwg format.
Some sources indicate the following.
Your first option is to simply save your 2D drawings in CAXA directly as .dwg files, instead of using CAXA's standard .exb file format.
As an alternative, you may try to use CAXA's Bulk File Translation tool, which allows users to create .dwg version of complete .exb drawing folders.
We haven't, however, been able to verify those steps.