Example:
set address name="Local Area Connection" static 10.0.5.99 255.255.255.0 10.0.5.1 1
The syntax is:
set address [name=]InterfaceName [source=]{dhcp | static [addr=]IPAddress [mask=]SubnetMask [gateway=]{none | DefaultGateway [[gwmetric=]GatewayMetric]}}
Более подробно вы можете почитать на http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/winxppro/proddocs/netsh_int_ip.asp