netsh add new interface
netsh interface ip set address name="Local Area Connection" static 192.168.1.15 255.255.255.0 192.168.1.1
Local Area Connection - the name of your network interface.
192.168.1.15 - network address (ip address).
255.255.255.0 - network mask.
192.168.1.1 - default gateway.
also see this site for more useful commands