Adding route information in a Windows 10 VM

Is there a trick to editing route tables in a Windows 10 VM in Hyper V?  I have a virtual switch associated with a virtual network adapter in the Windows VM.  I need to interface this to a network emulator in another VM in Hyper V.  From a non virtual machine I would normally use "route add...".  However, whenever I try to do this in the Windows 10 VM I get an error message:  "The route addition failed: Element not found".  Any suggestions?  Thanks.