using procmail to handle .forward files?

Hey people -

I'm looking into using procmail as my local mail delivery agent.  The main
reason is that I would like to restrict off-site users from 'bouncing'
mail off our servers without breaking the functionality of .forward files.

I was wondering if anyone had had any luck at getting procmail, rather
than sendmail, to handle users' .forward files.  I can get rudimentary
(just forward if the file contains a single valid address)  support using:

:0 ic
* ? test -s $HOME/.forward
! `cat $HOME/.forward`

But the rest (multiple addresses, pipes, etc...) would be quite complex,
and I thought I would check here before trying to hack out the rules
myself.

Anyone worked this out already?

Thanks,

                                        David Lowe