I'm assuming that the Cisco is on the same physical network as the Netopia.

On the special machine, give the NIC two IP addresses, 192.168.200.n and 10.213.161.5. Make the default gateway the Netopia and add the Cisco as a second gateway.

That should work but if it doesn't, drop to a command prompt and use the ROUTE command

route -p add 10.0.0.0 mask 255.0.0.0 <CiscoIP>

type route /? for more info.