[RKDinOKC]

Set up your device doing NAT (that turns yout public IP from cox into a private IP on your network) to make the computer you want to share a local host. Mine would be my Apple Airport. The host setting is under network, advanced. This will set the router so all incoming connections will go to that specific computer. Can also set the computer so it has a local fixed IP address and NOT dhcp. if you don't have an Airport Utility for you PC, you can put one on you iPhone.

You should also be able to setup a public dns name on the router.

I am not sure how to set up dynamic dns, I pay more an have static IPs. Think dynamic dns is a free service that lets you setup like glen.cms-okc.com to point the Public IP address of your cox router. And download some kind of software that tells dynamic DNS you have changed IP addresses.