I am sorry to have a disappointing answer, but as far I know running multiple vCPU for Linux host on Hyper-V is still not supported. Though you might want to digg more information from the following post:
MS Hyper-V Virtual Networks Configuration & Hyper-V Server settings.
That post seems to cover Hyper-V installation & networking in details with step by step snapshots. It might be helpful.
Enjoy,
Erick,
IBM TSM - Tivoli Storage Manager Guru