My son was doing some mod-rewrite trickery and hacking the tools.php years back. I haven't needed better url's in a long time though. So he stopped messing with presta and starting working with the IBM WCS (WebSphere Commerce Suite). Heck he gave up drupal, xoops and impresscms. He rewrote all of impress pulling smarty out and hooking it up php template.
Im not sure exactly what the op above is asking to do compared to the setup in tb & presta now. As i have been away for a number of years from all of this. I just remember him hooking me up with my url specific requests back in the day.
I'll shut up now and go away!