Hi guys

Ive hit a problem here and cant seem to find a way out

I have a site that started life as a subdirectory of a domain.

http://www.hostdomain.com/mysite

This little site has grown quite large and has a good SEO and link basis built up over the last couple of years, I decided to split it into a domain in its own right on a seperate server.

http://www.mysite.com

So I want to 301 redirect all traffic that went to the original location to the new location, I have over 500 pages on the site so a htaccess file for file would be tedious, but when I try a rewrite, I keep getting the 'mysite' subdirectory appended to the mysite address. Like www.mysite.com/mysite/file.php

Can anyone help please