How to add multiple Attendees per Event (Booking)

I'm looking for a way to register a person for a event, but when they register, they potentially take up more than one seat. eg: PA books an event for 5 office staff. The Event form just takes the PA's details and how many seats she'd like to reserve.

Then when you look at the CMS Desk Events module, you see her name, with an 'Attendee Count' column and the value of 5. Of course this would need to decrement the seating capacity of the Event accurately.

I've looked at creating my own custom Event(booking) object, but the CMSDesk Events module seems hard-coded to ONLY use the default Kentico one. So it seems like a lot of work to modify the Events module pages to get this to work.