I figured I do one for the existing Makebid Auction as well. I tested it here:
Still, it's not updated in version, but modified to work without adaption to your Makebid Software. It goes into the dispcat.pl subsection. If you use subsection dispcat2-9_pl, you possibly have to rearrange, I did not cross-check.
Let me know if and how it works...
If you don't know where you're going, any road will get you there.