Hello Shawn,
This does not look very complex to me the way I understood the requirement. The following solution is in the same lines as Raymond suggested. I have tested this in one of my Infoset Queries and found working well.
Step1.
Create a Selection Parameter say USERDATE in the Infoset Extras > Selections
This adds a Parameter field User Date in the Selections Screen.
Step2
Now in the Extras > Code > Record Processing give the following line.
check resb-bdter >= userdate.
Note that resb-bdteris to be replaced by your Date field which needs to be overridden by the Userdate of the Selection screen.
I saw this working. ( Please do not forget to run SQ01 afresh everytime you make changes to and Regenerate SQ02 )
Hope this helps you.
Regards
KJogeswaraRao