[exim] redirecting spam

I have spamassassin integrated with Exim thru
the exiscan patch and its working well. Right
now, I have a simple setup wherein spam is
handled with a header addition and a filter
which changes the subject to include a SPAM
marker in the subject line. I am also including
the spam level and spam report in the headers.
This is being done for all email which is processed
by the server.

What I need to do is only process email for the
local domain (there are several domains for which
we are secondary MX) and also to deliver spam to
a separate mailbox for each of the local users.
Unlike the system mailbox, this spambox will be
a file in the users home directory.

I have tried a rewrite rule with no luck and so
am looking for assistance from the list.

Thanks.


Andy R
(one of the original smail-3 gang)