BuddyPress.org

I am working on a Buddypress plugin install on WordPress 3. I am trying to setup the Buddypress registration to only allow new user signups from a specific domain (like: schoolname.edu). I have searched everywhere for a solution. I have installed a few WordPress plugins that are supposed to do this very thing – essentially whitelist a certain domain. However, this doesn’t seem to impact the buddypress / register page when I signup a test account. Any domain gets through.

I know WPMU has a built-in feature for “Limited Email Registrations” – and that’s exactly what I need – except I’m using regular WordPress.
http://wpmu.org/the-wordpress-mu-guide/site-options/standard-site-options/

Has anyone done this before? Please help! Thanks!