Adding suffix to drawing number on drawing card using checkbox

We make outline drawings of our parts by creating a configuration of the original part/assembly so we can change the drawing title.

Currently on the drawing card we set the \$PRPSHEET variable to make the drawing number coincide with the part/assembly number.

Our outline drawings use a '-C' suffix to the part number designate them as Configuration/Outline drawing.

Is there a way to use a checkbox on the drawing card to add the '-C' to the Drawing number so we can save it as a separate entity in EPDM?

SolidworksSolidworks Pdm enterprise Pdm