Allocating network in Hyper V cluster via VMM ?

hi

I have two hyper V hosts with two 10Gbe physical network adapters. I have followed this link to create logical networks

http://technet.microsoft.com/en-us/video/tdbe13-network-management-in-system-center-2012-sp1-vmm.aspx

I have not applied the virtual switch to hosts yet because I want to assign it at the time of creating the Cluster .  Because I I've read that "Realize that logical networks for external virtual networks that have already been configured on the hosts do not appear in the list."  on http://technet.microsoft.com/en-us/library/gg610614.aspx

In create HyperV Cluster wizard it is not listing any on my logical networks . Can anyone suggest what else do I need to do to be able see the logical networks on the HyperV cluster creation wizard

   Can anyone please help me ?

Thanks

mumtaz