I may be able to give you some pointers (I've assisted with the architecting of banner ad class libraries before) but I'm a bit sketchy because of the lack of detail.

What exactly is it you want? To create banner ads from within a CGI script? What are your business requirements? Do you need to track click throughs? Do you need to create banners based on customer profiles? What do you mean by "maximize banner exposures using perl?" You could simply write a CGI script that creates a page that holds a banner ad and respawns itself in a popup window ad infinitum. That would pretty much maximize banner exposures, but I don't think it's exactly what you want ....

The level of assistance you receive will generally be proportional to the effort you put into the question. In this case, you apparently spent about 12 seconds writing the question. I'm going on 60 seconds writing this response, which is 5 times the effort you put into the question, so I think I should stop now ....