Need help configuring zones and campaigns (please read to understand)

[Erick]

We have a website that has three specific locations for ads (homepage top, left and bottom). 

However, our site content is displayed based on the user's profile and the specific content that they want to see.  

Example - the site has 4 main topic areas (A, B, C and D) if you choose that topic C is your preference, then all the content delivered on the pages of the site will be related to topic C.  The banners will still be in the same positions (top, bottom and left).  The site is dynamic so it is one page that the specific content will change, so i cant create separate "home pages" for each and make a campaign for each.  

I need to be able to deliver the ads based on the Topic area that the user selected.  So I might have 4 banners for an advertiser; one per topic.  And if the user Choose Topic C, then the ads that are shown on the Top, left and bottom should be selected from the ads in the TOPIC C pool. 

So it seems that I would need to create 3 locations for the banners (top, left and bottom), but then each location will need a zone???  

I hope this describes what I need correctly

1) Can this be done?

2) How do I setup the Topics areas and banner locations?

3) How do I create the invocation code that will work with the variable which tells the ad server which Topic is chosen?

Thank you