Making more then one domain load a single site is easy on the NodeHost panel, it's done just like the default domain.
First add the new domain as a Secondary Domain, this makes it act like regular domain and it will get it's own DNS area.
Enter the domain you want to add and it will set it up for you on the panel.
Now to get it working all you need to do is update your new domain to point to our NS (NameServers) that you can find under the DNS area, or enter the DNS info on your DNS provider of choice like CloudFlare.
When you want to remove the secondary domain it will also remove the DNS zone, and www. alias for you.