Apache - redirecting authenticated users to other sites

Hi everyone.

Im really new here, so please have patience with me if i act out of order in any way. I do have some unix experience, but i would not call it extensive.

The problem i am about to describe probably have a easy solution, but i have been unable to find it while speaking to Mr.Google

The issue:
A while back i started an Apache web server (SSL), its running on OpenBSD 4.8, that connects to the internet.

On our local network we have two other web servers, also Apache running on Ubuntu 10.10.

Im searching for information on how to do the following:
If a user is correctly authenticated, how to redirect that user to one of the internal web servers?

I do not expect anyone to provide me with a how-to, im only asking for directions to where i can find this information. After all, reading about it and doing the DIY process is half of the fun

define "correctly authenticated". What are you doing?

Sorry for being unclear about that.

For anyone to be able to access the site i use
AuthType Basic
together with SSL.

So you want them to log in on via a webpage on an external facing Apache server and then, after authentication, be redirected to an internal Apache server? How do you expect them to be able to access the internal Apache server from the internet? Tunnelling via the external facing web server or what?

Yes, that is basically what i would like to do if possible.
Not necessarily redirected straight away, maybe trough a link on the external web site.

"Tunnelling via the external facing web server or what?"
That thought never even occurred to me tbh, ill start searching for that, thnx.