Let's see if I've got this right..
Q: You are running both server and client off the same computer, and you're having trouble connecting to your own server?
A: To connect to your own server you should be able to type in your LAN-address, (127.0.0.1, might differ depending on hardware)
or you can connect by typing in localhost as the address you wish to connect to. (This is done through Minecraft -> Multiplayer -> Add server/Direct Connect)
Q: Your friends want to connect to your server through Hamachi, how is this accomplished?
A: Start up Hamachi, get a network running and have your friends join it. The IP they'll connect to is your Hamachi IP.
Shouldn't be a need to setup any IP in the server config at all.
The responses here are based off my memory of Hamachi, things might've changed since I used it, this isn't a recently tested solution for said problem.
You can/should try the methods I've mentioned, but they're not guaranteed to work for you.
Best of luck!