forwarding all mail except root

[Max <davros@cyclone.Stanford.EDU>]

I'm running smail and I would like to configure it to automatically
forward all incoming mail to a different host.  Should be easy enough
with an MX record, right?  Well, the catch is that I want all mail
sent to root to be deposited into a local mailbox in /var/spool/mail
and everything else to be forwarded.  Has anyone done something like
this before?  Any clues?

Thanks,
     Max