custom nameservers setup - WHM, Cpanel

I have a cpanel/WHM dedicated server, and I need to setup custom nameservers for one of my domains. Because my current WHM and cpanel configuration doesn't appear to be the same as the web tutorials I've seen, I keep running into a hurdle. This project requires the freelancer to add the custom name servers as additions to the current ones (I don't want to replace my current nameservers) and ensure that when I add them to my domain registrar, that they appear in whois lookups and everything works!