Basically, I want to set it up so that they can only register ifthey use an address that ends with "@siemens.com"
Thanks, ~Eric
If you want to kill two birds with one stone, and you are using LDAP, you can set up mediawiki to use LDAP authentication either through my plugin:
http://meta.wikimedia.org/wiki/LDAP_Authentication
or (probably) through remote user authentication:
http://meta.wikimedia.org/wiki/User:Otheus/Auto_Login_via_REMOTE_USER
V/r,
Ryan Lane