When I've done it before, I plugged the ethernet jack from my modem to a switch with the number of ports that I needed static IP's for plus 1 for the incoming line, so if you have 5 Static IP's and a 8-port switch, then you plug 5 routers in to the switch ports and each router would get it's own IP and then you can configure from there.
You could also do the above, but instead of 5 routers, plug in 5 PC's or 5 network cards in 1 PC or whatever your need to access the static IP's with. I'm not sure what you purpose is.