Hi Dominic,
If you're not comfortable installing php or cgi scripts or don't want to hire someone else to do it you might consider AffiliateCloaker at http://www.link-pro.com/affiliatecloaker.html.
AffiliateCloaker which will turn:
hop.clickbank.net?...
Into...
yoursite.com/link.html
The 'url' will be your site instead of ClickBanks.
Affiliate Cloaker is a Win 98/ME/XP app that sits on your desktop that converts ClickBank and other affiliate links into links with your URL in them, instead of the affiliate merchants site.
This not only gives you links back to your site instead of the affiliate merchant, but it also PROTECTS your affiliate ID from being stolen or subsituted by someone else intent on stealing your commission.
-Dave
Learn Professional Methods of Selling Digital Products on the Internet