It probably depends on how you are gathering the parameters for the stored proc.
If the web page gets the parameters it could set the values that you want in CR as parameters to the stored proc, then have the stored proc pass them back to the report.
If the user is entering the parameters for the report, and these parameters feed the stored proc, then I don't think that it is possible. As far as I know, CR doesn't look at / care about those things.
HTH