Crystal Reports Subreports

I have put together a report that uses a main report with one
subreport in the group footer section of the report.  The problem that
I am having is that I can not seem to find a good way to get to the
selection formula of the subreport, modify it, and have the refreshed
resuslts show up in the main report.  Has anyone else encountered
this?  Using the selection formula from Delphi for the main report
worked very well from what I saw, but I had to go through these
subreport hoops and barrels to display records that did not have a
detail report associated with them.  Any assistance would be greatly
appreciated.