Domino and Apache reverse proxy

I’m trying to set up an Apache Reverse Proxy for use with Domino. It actually works quite well except for one thing – it is not masking the “interior” host name. In otherwords…

If you go to http://proxy.site.com/webmail.nsf, which is proxied to http:/domino.site.com/webmail.nsf, then the URL in the address bar will change from proxy.site.com to domino.site.com. This sorta defeats the purpose of the proxy server IMO – I want to hide that information!

Help!