nixCraft

I'm a Newbe and I'm in trouble. Been reading a lot of books on Bash and I'm still not there yet still afraid to type something into the server.
Ok here's the problem, I have Hughes Net (not a good idea) and I have the pro plan. I have a fixed IP address form Hughes Lan1 IP Address 72.168.xxx.xxx subnet 255.255.255.252. I can only assign it to one computer, which is the server (LokBox 520) its IP is 192.168.5.1 and has 4 ports. Hughes modem will not assign the IP itself I have to assign it myself. I have on the Server bash-3.00$ and can log in as root or admin root. I need to assign the IP address from my Hughes Modem to the LokBox. The Hughes modem uses 192.196.0.1 subnet 255.255.255.0 and router address 66.82.xx.xx. I tried to use Redhat command and it didn't work i also have vi that I tried to use and couldn't get it to work. Can someone help me assign the IP to the Server?
thanks
don

am i missing something or the picture is incomplete or diagram mistake?

"its IP is 192.168.5.1 and has 4 ports" vs "192.196.0.1 subnet 255.255.255.0 and"
here its 192.168.5.* and there 192.168.0.* 0_o
could you please be more specific. and provide us with a network diagram viz
PC -> LAN -> Switch -> Router -> DMZ -> Internet
where you replace the resources with what you got in your network.