2 different subnets for 1 PC.

I have a small peer tp peer network that is using a Linksys Router with DHCP. 192.168.x.x numbers.

There is also a direct connect to another network 10.0.3.1

Both have a default gateway. How can I make both of these work? If I am on the 192.168.x.x network can I route to 10..3.1 ?

Can I use LMHOST files? Or something?