If the two domains are hosted in the same account, you can simply rename the yourdomain.com folder.
For example, if the new domain name is newwebsite.com, just rename theirename.mywebsite.com to newwebsite.com And the entire site is moved to the new domain.
If you don't want to move the entire site, you can use shell command "mc" to move a specific folder.
Have fun in Unix!
Save $97 (MAX Discount) with code: [color=#CC0000]97YES[/color] [url=http://dreamhost.com/r.cgi?296804/signup|97YES]Sign Up NOW[/url] or More Codes here