setting up home test environment, want to get servers in range x, talking to y

hi 

i'm setting up a test domain environment at home.

using windows server 2008 R2, running virtually on oracle virtual box.

i have my domain, contoso.com set up  (10.0.0.1)

my broadband is pre-configured at 192.168.0.1

whats the handiest way of getting the domain talking to the broadband, for internet access on the test domain controllers??

thanks.