Any ColdFusion query object can be passed to <cfreport> (quote from Ben Forta's "Macromedia ColdFusion MX7 Certified Developer Study Guide"). So assuming your stored proc returns a query, it doesn't matter if you use <cfquery> or <cfstoredproc> to call it, in both cases you should get a query back. And regardles of how, that query can be passed. I'd expect something like this to work:
<cfstoredproc datasource="MyDSN" procedure="MySP">
<cfprocparam cfsqltype="CF_SQL_DATE" value="#form.StartDate#" />
<cfprocparam cfsqltype="CF_SQL_DATE" value="#form.EndDate#" />
<cfprocresult name="yourData" resultset="1">
</cfstoredproc>
<cfreport query="#yourData#" ... >
(I never use cfreport myself, but the online documentation wraps the name in # # instead of just passing the name as a string, so I assume that's correct).
