Referral link system for membership site

This is part 1 of the overall project. Part 2 will be done later on by the same person who does part 1. A separate project will be posted at that time. Part 1. I currently own a community website that runs on an Oxwall engine. I'm looking for someone who can either create, or install a script they already have (and tweak it to suit my site) which gives each user a unique referral link which they can share with friends, etc. When the link is clicked they are sent to the site's sign up page and if/when they sign up the referring user gains a point which is shown on their profile. Note: the site is new and only has a couple of members so there wont be any problems of a busy server. Part 2 will be discussed with shortlisted bidders. Website link will be given to those who ask for it :) (not in a copy paste pitch)