Intranet -> Squid -> Firewall Proxy -> Outside World

Weee. Here is a little situation that hopefully ya'll can help me figure out.

Assume the situation where a company has an intranet. All web access from
the intranet->intranet do not go through the firewall proxy. Any intranet->
internet requests goes through the firewall proxy.

Can squid be placed behind the firewall proxy such that all internet requests
go through squid and then through the firewall proxy? If so, how is the
proxy designated in squid's config?

If this is possible, assume that any intranet->internet accesses require user
authentification to go through the firewall. The firewall proxy is
Netscape's proxy and clients are Netscape's navigator. Whenever the first
attempt to access the internet, a dialog pops up asking for
username/password. This is then cached for future access for that session.
There username and ip are recorded and is used to bill individual depts. for
internet access.

Now, if squid can be placed behind the firewall proxy, will authentification
still come from the user or will squid need to authentificate itself to the
proxy? ie, will the logs report no users browsing, but squid has accumulated
10,000$ of access :) ?

Any help would be GREATLY appreciated.

-- 
_______________________________________________________________________
Chris Richards                         | Texas A&M University          
richards@tamu.edu                      | Department of Computer Science
http://www.cs.tamu.edu/people/richards | Internet Publishing Services
http://grover.bre.com/                 | Internet System Programmer