[Chilli] Per-user/group content filtering

[Rampage]

Hello everyone,
i know that web content filtering is a bit behind the scope of
coova-chilli, but i hope someone can come up with a brilliant idea and
help me out solving this dilemma which appearently i can't solve on my
own (shame on me! :( ).

Basicallyi have a flowlessly working coova-chilli authenticating users
against a freeradius server and forcing the users traffic through a
transparent proxy.
The transparent proxy solution i'm using now is based on dansguardian +
squid.

i use the HTTP_POSTAUTH_PROXY directive and a custom firewall rule
script to accomplish the task.

The problem is that in this way, the only data the content-filter
(dansguardian) knows, is the ip address of the client which previously
authenticated agast the captive portal.

As you may know, is there any way to have the username forwarded to the
proxy so that it can perform proper filtering based on user/groups profiles?

Do you know of any nasty trick i can eventually use to let the proxy
know about the identify of the user?

thanks everyone for the support.
SIncerely
Francesco