Someone can correct me if I am wrong, but you really don't have to worry about the router. Just assign a static IP on the system that falls with in the network address your router uses.
In TCP/IP settings on the server choose the staticly assign option then type in the IP. (right-click my network places, go to properties, click on local ethernet, and then hit properties for TCP/IP)
Otherwise I looked at the router and I didn't see any options to set static IP other than Static NAT in firewall settings that looked like it would assign the same IP ot the sytem instead of dynamically resolve it.
To answer your other questions, no ISP is going to block port 80. That's all of your web traffic. And the 18.104.22.168 Ip is your public IP address. You will assign a static internal address (192.168.1.x) then use port-forwarding to get inbound traffic to the correct spot. (if there is any)