Accessing LAN Segment from Shared VM

Well, the title said it all

I'm running WS 9 at work and would like to set up some shared VMs that can be accessed from other WS.   The VMs however can't get on the network directly - they sit behind a virtual firewall and communicate with one another via custom LAN segments.  My initial testing would indicate that Shared VMs don't have access to these custom LAN segments.   Is that truly the case or am I setting something up wrong?

Thanks

J