John,
If your user is going to create pages in Dreamweaver, then just have him upload the files into a subfolder of the Drupal root directory...and they will load completely independent of Drupal.
IE:
Drupal Directory == /foo/bar/htdocs/mydrupalsite
User's DW files directory == /foo/bar/htdocs/mydrupalsite/dwsite
His pages will not be affected by Drupal at all. You just have to be careful when upgrading/updating that you leave his folder structure intact.
With this method, you don't have to do any htaccess redirects or anything like that.
...........................................
Nick Young
Outreach, Communications & Consulting
Office of Information Technology
North Carolina State University
Box 7109, Raleigh 27695
Ph. 919.513.2716 | E-Mail: njyoung@ncsu.edu
Web: oitdesign.ncsu.edu