I want SA to filter only certain users

[George Bell]

I installed SA through my cpanel hosting account (9.4.1-STABLE 65) but I don't know which version of SA or how it is invoked.  It creates a spamassassin folder which contains a user_prefs file(no file extension) & this will apply the rules to all users for that site correct?   Can I use SA on only a few users and not the rest.  I want to test it on a few users that get tons of spam daily and have spam sent to another folder.  I don't want to check a spam folder for all the accounts everyday so I figure once I get this working well on the few accounts I will then just set it sitewide & delete all spam.    Is there a way to do this or how do I apply different rules for individual users? I see references to .cf files in other posts but I don't seem to have the same files or folders in my setup and there is nothing with a cf ext?   Thanks, -George