MS Proxy 2.0 domain permissions

Hi,

We have MS Proxy 2.0 with SP 1 running on NT 4.0 SP 6. I try to restrict user access to a particular site, but some of them have a legitimate rights to access this site. Is it possible in MS Proxy to differentiate the access for users? Or is it “all or none” thing? I can restrict the access for everyone no probs, but I would like to give the access to some, and restrict for others

Thanks in advance,

Arthur