Here is a scripted explanation of the CNAME requirements you can use to help communicate the LaunchRock CNAME set-up with your Domain Host:
"Hello,
My Domain Name is hosted by you, and I need your help creating a new CNAME Record.
I want to create a CNAME Record for a subdomain I have chosen, and LaunchRock has provided me with a destination where they will host it.- The CNAME I need to create is_____________ [replace with the subdomain you chose, e.g. "signup" if "signup.yoursite.com" is the URL in your LaunchRock Domain Settings].
- The destination it should point to is "host.launchrock.com"
In other words, I need a CNAME Record [_______________] that points to host.launchrock.com."