Apache Reverse Proxy with authentication

We currently have an Apache 1.3.xx server that isn't doing much, and an 
IIS 5 box we use for development work.  I would like to move the IIS 
machine behind the Apache machine using mod_proxy, and use http_auth to 
verify they have access to the dev box (and what directory they have 
access to).  Once authenticated, they are reverse proxied to their 
development site on the IIS box, where a virtual host can reply to the 
request.

For example:

Client logs into Apache via mod_auth_whatever (or a PHP script).
Client is authenticated.
IP address of internal virtual host is sent to mod_proxy.
Apache forwards requests for specific client to development web server 
(based on development server IP), based on auth info.

Is there any straightforward way to do this?


--
Gene Cronk ISSAP CISSP IAM
Systems Administrator -- The Robin Shepherd Group
http://www.trsg.net
Office: 904-359-0981x36  Cell: 386-795-3081