DD: you can do it at the WP-CONFIG level so long as you are using an IP or a subdomain (you can't put in the actual real domain since it resolves somewhere else, unless using the HOSTS file method, then certainly you could use the actual domain.) Simply follow the directions on the link below and put the new IP where the new site and install wordpress there.
http://codex.wordpress.org/Changing_The_Site_URL