Easy cookie and php job!

A nice and easy project based around cookies! I need a freelancer to write me a small script – when a visitor comes to my site with a specific url then a variable is entered into a line of php code. Example; [login to view URL] This would enter the value 7216 into a cookie. If the user then went to my purchase page the value 7216 is put in the url; [login to view URL];virtopaccref=7216&frames=Y&bars=Y&FirstPage=Chooser&Chooser_Range=44800 If the user doesn’t have the cookie set then another value is put in the URL. If the user arrives with this link; [login to view URL] Then the code 2300 is put in the URL [login to view URL];virtopaccref=2300&frames=Y&bars=Y&FirstPage=Chooser&Chooser_Range=44800 Good luck!