David,
I think (I am not sure) that an export to DXF/DWG is driven by dxf_export.pro file, only. This file is located in CR2_loadpoint\Creo 2.0\Common Files\M070\text\intf_configs directory. Also config.pro option INTF2D_IN_DXF_MAPPING_FILE can be used to specify a path to custom export file.
Martin Hanak