Exclude objects from Alerts using Labels

Hi,

i want to exclude certain objects from Alerts in an easy way using Labels (i guess that is the most easy way).

Let's say i want to exclude some VMs from the "Guest storage space utilization" alert.  I can add a label called "ExcludeFromGuestStorageSpaceUtilization" and set that to "True" for the VMs i want to exclude.

But then i need to change the Query for the alert to have an exclusion for all VMs where ExcludeFromGuestStorageSpaceUtilization does not equals True.  How do i query this (so i need to basically do a NOT EQUALS or something like that).

I can't set the query to all VMs where ExcludeFromGuestStorageSpaceUtilization equals False because that will mean i have to set this property on all other VMs that i don't want to exclude and that's pretty labour intensive...

Thanks!