I have a few things over at my site: theselights.com . The ESX to vSphere migration posts should have what you need. Here is the VM registration piece:
#----{ Register VMs that were chosen to be migrated
Write-Host "Registering VMs to: " $newVC
Foreach ($vm in $vmsToMigrate) {
dir $storePath | where {$_.PSChildName -like "*$vm*"} | % { New-VM -vmhost $vSphereHost -VMFilePath $_.DatastoreFullPath } | Out-Null
}
The variables get set earlier in the script so I would recommend checking the full thing out. There are other scripts on there that will break your SnapMirror, find all VMs on a datastore, etc.
Thanks,
Erick