Is it possible to use the web.config <location> element on an Umbraco site, and if so, what URL to use?

Basically, I have a normal website with a single page in an admin area that could potentially have a longer than normal response time. For various reasons I can't queue this particular process, so I want to increase the script timeout for this page only.

I've put the path in as myadmin/longrunningpage, which is the actual URL I am going to, also tried adding the .aspx, and no joy - any ideas?

(I know it's not API, but Our Umbraco doesn't seem to have a forum set up for general comments like this!)