No it's not possible to do this in Cloud Code. Your best bet would probably to have a segmented version of the particular Virtual Good set up and then move the players into a particular segment. You could also make use of Virtual Goods tags here too. If a player is eligible to see a certain Virtual Good you can use the tag to return a particular list of Virtual Goods for them. Create and deleting configuration on the fly like this would work as you would need to publish a snapshot for the configuration change to be applied.