Need to setup domain to forward to offserver url

How can I setup a domain to forward to offserver url(another domain)?

To explain this better what I am trying to do is get my domain initialdomain.com to forward to accountname.myorderbox.com but still retain my domain name initialdomain.com(cloaked).

I hope that makes sense, the way I am currently trying to do it or as I have read around the net is to modify or add a cname like such:

Please let me know if this is correct or if I should do something else. I have tried it out but it isn't working but maybe I am meant to wait 12-24 hours.

I also read somewhere that I can not do this with sub-domains but only tlds.

I hope that someone knows more about this and can help me out.

Thanks,

DarkG