dv port groups in vcenter 5.0

Hello,

I would like to get the list of dv-portgroups from vCenter 5.0 which is associated to a particular dv switch. Can anybody guide me how we can get it.

Also is there anyway to get a list of  the vSphere network (portgroups) in vCD's with its external networks or port groups alone.

Let me know is there any possible ways with samples if anybody has.

Thanks