1. Log onto your GoDaddy account. (http://dcc.godaddy.com/)
2. Click "My Account" on the top left.
3. Click the "Manage My Domains".
4. Click the domain you want to use.
5. Click "DNS ZONE FILE" at the top of the page
6. Click"Add Record”.
7. Follow the steps below that apply to you. Read each section and decide what is right for you.
8. Set "Record Type" to "A (Host)".
9. The "Host" section is where you enter your prefix (i.e. If you want "mc.servername.com" enter "mc").
10. On the "Points to" section type your numeric IP (do not include a port).
11. You can now use this domain with your port to connect to your Minecraft server (e.g. mc.servername.com:1234).
Once you have made your changes click "Save Zone File" at the very bottom of the page.
Allow for 48 hours for the changes to take effect.