How to pass the final recipient to a pipe command

[Michael]

Hi,
in master.cf I've defined a Procmail service that pipes a mail to  
Procmail for content filtering.

procmail  unix  -       n       n       -       10       pipe
  flags=Rq user=vmail null_sender= argv=/usr/bin/procmail -m  
/etc/procmailrc ${sender} ${recipient} ${domain}

The ${recipient} variable always passes the recipient passed from the  
sender. But when the recipient is just an alias, Spamassassin will get  
the wrong recipient information.

Is it possible to pass the final, not aliased recipient as an argument?

Thanks,
Michael