You can use Google API. I thought Google started indexing dynamically generated site.
Google API
http://www.google.com/apis/
Also, my comment to what you are trying to do would be: why don't you look for a way to make your site serach-engine-friendly instead of looking for a dynamic-site-friendly search engine?
One way to do this, if you run Apache, is to take advantage of mod_rewrite. Here's a very good resource from Apache in doing so:
Module mod_rewrite URL Rewriting Engine
http://httpd.apache.org/docs/mod/mod_rewrite.html
Apache 1.3 URL Rewriting Guide
http://httpd.apache.org/docs/misc/rewriteguide.html