nt user groups and squidguard

[[VL]Sparkz]

hi guys I got squidguard setup and running great. I can set it up to distinguish between machines using an IP based ACL but how do I set it up to use NT based user groups. How do i pass the NT groups to squidguard so I can distinguish between these groups Heres my problem. I have an NT domain with 800 users seperated into year groups and I want to give more access to the sixthformers and less access to the younger groups. Is this possible.   Lookin forward to your replys Thanks Sparkz