If these are parameters, you're not going to use shared variables. Instead, in the report design you need to go to the Subreport Link and do the following:
- In the top, select the SubmissionControlId parameter from the main report.
- In the bottom, turn off "Select data in subreport based on field:". To the left of that, drop down the list of Subreport Parameters and select the one for the SubmissionControlID.
This will link the parameter from the main report to the parameter in the subreport.
-Dell