Well, i think that you need the NoIP site.
1st create an account, then go to "Add a Host" icon.Put the info you want there and you're done.
You only need to edit the Hostname and chose what host you want.
Example: myserver.no-ip.org:27015 (27015 is the port that you have opened in YOUR router for your server, so you may change that)
If you want to keep "alive" a host, download No-ip DUC and set it to run when you open your pc so the host will be always updated.