For example, if you picked signup.yoursite.com as your address, enter: signup.
In the points to box, enter host.launchrock.com.
Review your changes, and click Continue to create the CNAME record.
Congratulations! Your CNAME record is now configured to point to LaunchRock.
If you have trouble configuring your CNAME records, you can view a sample message to use when you contact Register.com for assistance.
Once you've modified your A records, it may take up to 72 hours for changes to update live.