there are 2 ways.... the hard way is to setup a local dns server.
the easy way is to edit the file /etc/hosts.
for example, my /etc/hosts file is....
192.168.0.1 tyler.durden.net tyler
192.168.0.2 marla.singer.net marla
so if i give the name "tyler" or "tyler.drden.net" the program will use the ip address 192.168.0.1 (the address of my local server)