We have a situation where we want to rename about 550 HTML pages. In doing so, we want to 301 redirect the old pages to the new ones.

All:
What is the easiest way to do this? We are running Microsoft IIS. I don't want to burden the system admin (not me) with having to a manual operation on 500 + pages. Besides going from html to .asp the names will totally be changed from like abcd123.html to my-optimized-keywords.asp

Has anyone used a custom handle 404 page to handle the 301 redirect? What is your experience with it? Any advice/suggestions are appreciated.

Thanx,