DS 4.2 no match score substitution parameter based on global variable

I have a DS 4.2 batch job which has a groupx (group1 - group5) global variable to be passed as a parameter to determine source records pulled and which target tables to populate.  However the groups need to have a different no match score for vendor name:

-group1 - group4: vendor name no match score = 60

-group5: vendor name no match score = 99

I can see the no match score can reference a substitution parameter but what's the best way to populate a substitution parameter based on a global variable prior to the match?

Thanks...