What is the best strategy using the FIM cmdlets to list all Criteria-based security groups that have NO members?

I want to create a list of criteria-based Security Groups (membership locked) that have no members that match the criteria by using FIMcmdlets.

I can get a list of these Groups easily enough with a customConfig filter but how can I then grab the list of user objects generated when I push the "View Members" button on the Portal form from, within Powershell.