Web Site Table of Contents

I'm having real problems creating a table of contents for a very large site. I've used Mark Howard's Index Generator which is good, but I need to create a tree view of the site.

***This has to use the file titles AND headings within the files*** - it's the headings that are giving me the problem. Really I need to do something that's pretty easy in Word/PDF but seems to be hard with a website!!

Any tips much appreciated. Thanks.