Attendance List (Nodereference etc..)

I have a very interesting project that I am working on right now and I would like to share one of the obstacles that I am facing.

I am working on an attendance list for events that we host.

We usually host multiple events in a selected city.

So the process is that we have an online form that we fill once we have an attendee confirm his attendance to a selected number of shows in that city.
----------Booked Person Form-------------
The form: we take down the following info
firstname
lastname
company
list of shows to attend (created using nodereference from nodetype "event")
-----------------------

now the problem that i am facing is that we try to create an attendance sheet before the show (list of all participant) and then after the show we take down the names of the people that showed up at the event...

Attendees that came to the event should be entered into the system so we can keep track of how many showed up for future stats.

now if I pull the booked person node which has the attendee name and shows that he is booked for, I can't really mark which show in specific he attended. I can create a general "Yes/No" attended button but in return this will mark that person as if he attended all different the different events in that specific city (could be 1, 2 or even 10 events)

Now, how can we make this possible... how can we mark a person "Attended the show" for a specific event and not all of them at the same time.

This should be easy enough where you can see a list of all the attendees of the specific event and then mark who showed up and then hit submit...

now is that possible? I know it is but I have not figured out a way of doing it yet...

any help there.

Thanks in advance