two things I am attempting to do

[Noah]

there are two things I am attempting to do.  What is the best approach 
to both.

1) I am running spamassassin site wide.  I'd like to move the mail 
message identified as spam in ~/mail/Spam directory

2) If a user does not exist and there is an username entry 
/etc/mail/virtualusers to forward mail and discard all mail that is 
identified as spam.