Reward members for clicking on an affiliate banner

[estado3]

I am looking for a simple explanation of this step by step process, I am extremely new to php, and I am wondering how this can be achieved,  I am planning on rewarding members who click on banners on my site, o far my site does not have a membership database, I am wondering if I could use phpBB or any other script such as joomla with a membership registration database/process, and show members a banner from my affiliate, and if they were to click on the banner and carry out a sale, reward the member a certain number of points in my points database .  I am also wondering how I would know if the member has completed the sale from my affiliate, other than having to log on to my affiliate site, and manually see if they have.

 

Any help and the steps involved in doing this would be greatly appreciated.