having endian mercury 50 redirecting www to an external ip

[Guest]

[conceptmedia]

Hi all,
I currently have my webpage hosted by our linux server, so on the endian hosts section we have host ip address: 192.168.100.1, hostname: www and domain name: conceptmedia.
Now we want to host this web page on a external web server.
Question is do I have to change the host ip address in the endian host section to reflect the new ip and also the dns records of our internal server?
I've done that more than 24 hours ago and nothing happens, it is still showing the html host by our internal server.

Manythanks in advance for amy advice,
Pedro Gomes