going thru the custom evar route or piggybacking an existing evar, and is there a way to auto append like a variable to page URL, so if some clicks on slot 1 on the home page, it tracks as "slot 1"?

Internal promotion banners on the homepage direct to a different part of the site.

Is there a report that exists in the adobe suite or is it a custom report? I'm trying to understand the performance of my banner slotting which ones are getting the most traffic and attributing to revenue.