Crystal Reports Pass parameter to SubReport

Message

     Hello All,
I have a bit of a problem and I'm not sure if this is something that can be done.  I do appreciate any help you can give me on this.  I have created a report with 2 subreports.  The main report will have a date range for a column called 'Referral Date'.  One of the subreports will have a date range for  a column Status Date and the other has a date range for a column called Approved Date.  I've created 2 formulas called @startdate and @enddate and also 2 parameters called ?startdate and ?enddate.

On the main report for the selection criteria I have a formula
     {Referral Date} >={@startdate} and {Referral Date} <= {@EndDate}
On the first subreport
        {Status date} >={@startdate} and {Status date} <={@EndDate}
On the second subreport
   {Approval Date} >= {@startdate} and {Approval Date} <= {@enddate}

I'm not sure what to do next to make it work.  Any help is appreciated.

Thanks,

PELLIS