Properties for appointment sent to entire post office

I have a user that sent an appointment to an entire post office for a building wide meeting. They used the wildcard format of *.PostOfficeName. Now they want to know how many people accepted the appointment so they know how many chairs to setup and how much food to order.

However, because the appointment used a wildcard, the properties page of the appointment only shows one line:
To: *.PostOfficeName Delivered.
It does not show each recipient and when whether they accepted or declined.
Does anyone know of a way to get this information when an appointment was sent using a wildcard?