If you are looking for the VMs on a specific datastore, you could do something like this.
Note the use of the Sort-Object cmdlet to get the VMs sorted by name.
$dsName="MyDatastore"
Get-VM-Datastore$dsName|
Select-Object@{N=”Datastore”;E={$dsName}},Name,VMHost,UsedSpaceGB|
Sort-Object-PropertyName|
Export-CSV"\\DIR\test.csv"-NoTypeInformation-UseCulture