[squid-users] how to deny acces to some users listed in a testfile

[earthtirol]

hi

i want a acl that
        * all have user have to authenticate
        * but for some users surfing is only allowed on a single surfstation

the first acl implemented requires all users to authenitcate, no problem
but how do i create a acl that points to the users list?

this two acls should then be combined 

        acl password proxy_auth REQUIRED
        acl surfstation src 192.168.0.101
        acl surfuserlist ??? userfiles
        http_access allow password surfuserlist surfstation

thanks hans-peter