Referrer URL on registration

[Kanustep]

Hello,

I would like to ask if someone can code a way to include the referrer URL on registration e-mail.
I'm not looking for referrer user but for referrer URL, this way I would be able to know exactly each user come from X or Y URL address.

Then if some URL does matter it will be useful to make promotions and prizes and to show to those people who came from a particular URL.

Thank you, hope someone could code it or tell me where I can find a hack to include the referrer URL on registration e-mail.