filter spam from inbox

I have recently setup Mailscanner and Spamassassin on our mail server 
(Sendmail, Procmail, Courier-POP3, SQWebmail). I have it setup so that 
all alleged spam is tagged and sent to the user.

Obviously, the users are able to setup filters and rules in their mail 
program (OE, Netscape) but some of them have asked about filtering in 
sqwebmail. I read that you can if you use maildrop. But, I would rather 
not have to reconfigure my server.

Is it possible to filter messages in the inbox based on a word in the 
subject? I'm not worried about filtering during delivery. I just want to 
be able to filter my inbox. Anyone have any ideas? Any help would be 
appreciated. Thanks.

Sean