Android :: Connecting To 3G And WiFi Data Networks Simultaneously?

We have an application where we'd like to use the WiFi connection on a local network (intranet) with no Internet connectivity, and use the 3G connection simultaneously as the data connection to the internet. To summarize:

We need to connect to two distinct networks at the same time - We need data traffic to be properly routed to the appropriate network based on its IP address - We need both radios (WiFi and 3G) on and active. This can easily be done on the iPhone, but not sure if it can be done on the Android.