There are a few steps you will need to follow to get this done.  The first is to get the IP address of your server:

1. Log into http://billing.guildlaunch.net/
2. Click 'My Services'.
3. Click 'Details' next to the server.
4. Log into the Control Panel.
5. Take note of the IP address and port.

The next step is with the registrar of the domain name you would like to point to your Voice Server.  You'll need to set up an A Record through them to point at that IP address - the steps vary from registrar to registrar, but once you've done that, it should be pointing properly and you will be able to connect using the domain instead of voiceaXX.guildlaunch.net .