so i have multi-site setup, shared user tables, separate content tables running:

www.example.com
www.example.de

What I'm trying to do is.

User Browser Lang en -> Requests www.example.com -> returns www.example.com
User Browser Lang en -> Requests www.example.de -> redirect www.example.com

User Browser Lang de -> Requests www.example.com -> redirect www.example.de
User Browser Lang de -> Requests www.example.de -> returns www.example.de

i also only want this to happen when requesting the domain name, not for interior pages.

i guess this is a two part question, 1: is this possible? 2. if it is, can this be done in apache, or does it have to be a custom module( and if so what hooks should i be looking at)?

i've looked at apache content negotiation, but I'm not an expert in apache so i didn't really see any examples that i might be able to leverage.

Any help / insight / suggestions would be greatly appreciated.

Thanks.

Brian

Setup:
PHP 5
Mysql
4.7.5
Apache
Linux - Debian