Thanks for the replies, folks.
Actually, my hosting's with DH but the .nu domain name in question is registered with Netrilium. I want to transfer the domain registration to Namecheap or Godaddy or somewhere else, basically, but apparently I can't. That's what I'm asking about. Sorry I wasn't clear. I was posting at work when I asked the original question and I was a bit tense!
Anyway, I hope some kind soul can advise me if it's possible to transfer the registration of a .nu domain at all. Thanks!