Yeah, since you didn't post your software version (please remember to always do this), I used CR 8 terminology.
You can pass variables from main<->subreports byt using shared variables.
Once the subreport has fired, you can use it in the main report, and example is:
subreport formula:
//@MyValue
whileprintingrecords;
shared numbervar Somevalue:= sum{table.value});
Then in a formula in the maqin report, again AFTER the subreport has executed, you can reference it's values, as in:
Main Report formula:
//@MyValue
whileprintingrecords;
shared numbervar Somevalue;
somevalue < 1000
so this would work as a suppress formula for sections after the subreport.
Stating that you want to "suppress stuff" isn't meaningful, please take the time to what you specifically need.
-k