Cache Question

I’ve been using WP Super Cache for a few months and it’s been extremely successful. Thanks for creating such an awesome and functional product.

I’ve recently run into a conundrum and am just looking for a little advice. I’ve written some PHP that based on referrer writes additional HTML + JavaScript that displays additional ads. What’s happening is those pages are sometimes cached and the ads are seen by an additional, irrelevant audience. Unfortunately this is not a script that’s isolated to a single page, so I can’t create an exception for it, it’s in the global header.php file.

Any ideas for a workaround here?

Thanks,
Christopher