creo4 config.pro option documentation for: EXPORT_3D_FORCE_DEFAULT_NAMING 
export_3d_force_default_naming
yes
, no
*
Determines whether to use the Creo
application file names when exporting to the STEP and Neutral formats.
yes
- Uses the application file names when exporting to the STEP and Neutral formats. You must accept the default file name.
no
- Adds a suffix to the model file names.