How to Customize Auto-Assignments in Match Collaboration?

In our organization, the person who entered the requisition ("Entered By"), is also responsible for entering the receipt of the corresponding sourced PO. In setting up the "Match Exception Group" for Match Collaboration, I do not see a way to auto-assign Rule_R500 (No Receipts Found) to the requisition entered by. Or is there? Is there a place for a User List or Custom SQL?

Any suggestions/work around to set this up?

Thank you