Simple A/B Split Testiing Script

This project will be a piece of cake for someone who has done it before. In fact, you may already have this type of script in your arsenal of tools. I so, you can deliver this project to me in minutes!! Basically, I am looking for a split testing script utilizing PHP and MySQL to redirect visitors to split test pages, set cookies, and track conversions via clicks This script must redirect users to one of up to nnnn (18 would probably be a maximum) different pages that I would like to split test. It must divide the amount of visitors EVENLY to each test page and remember the page each visitor visited so that the visitor can be sent there if he/she comes back to the site. Unlike most AB split testing scripts in the market, where the traffic has to come from an index (i.e. home pages) then gets divided to the test pages, I want this script to allow me to use any page as my source of traffic to then send them to the split test pages. THIS IS VERY IMPORTANT AND MUST FEATURE! So, Ideally, the script should allow me to determine the source page (where the visitor first lands), then allow me to determine what pages to designate as the test pages. Script must generate a status report for each test page (ie: visitors, conversions, dollar amounts, et..) and display it on a password secure admin page. Would also like a feature to export results in a Excel spreadsheet format. However, I'm flexible with this export feature if it will delay the project. Must allow for testing in a subdirectory of website, ie: /split/, not home page. Part of project is help with the installation of the script on a Unix server.