1 router, 2 IP addresses, 3 PC's

[privatedog]

I presently have a Netgear RP614 router taking a cable connection and sending it to PC#1 and PC#2. Both PC's have thier own IP addresses.
I would like to connect a third PC (Windows ME) to PC#1 (Windows XP) and share files, printer and possibly the internet connection. Is this possible using the same router (two slots open)? Do I need to add another router? Where would it go? Or is there another option altogether?
PC#2 would need to remain its own entity from this connection and keep its individual IP address.

[Tuttle]

You can just plug the 3rd PC into the router as well.

If the two IP addresses you're dealing with currently are RFC1918 private address space (10.*, 172.16-31.*, 192.168.*) then everything should just work. If either or both of those IP addresses are public addresses provided by the ISP, there may be a little configuration required on the router.