Firstly, 192.10.200.0/24 is, AFAIK, a registered Internet address. You should change that subnet to 192.168.200.0/24.
Secondly, the box on both LANs should automatically route between the two LANs. There should be no need to add extra routing to any box except those that need to connect to something on LAN2. The printer might be an exception there, but I'm not sure.
Thirdly, for NBT to route, you need a WINS server. Samba can do this automatically for you, you just have to flip the switch, so to speak. You also have to tell the PCs on LAN2 that the gateway machine is also the WINS server.
Finally, if you still need to fiddle with the routing in Windows 2000, type route on a command line for some assistance. Windows' routing is not quite as simple as routing in Linux, but it's not impossible. It basically does daft things like route through the loopback or some strange thing, so ignore that and it makes sense.
Wade.