Flag a node for a user by administrator

I need to do the following and i was wondering if it can be achieved simple and clean with flags :-)
If this isn't the right place to ask this, my apologies.

I have a pure administrative site, for a board committee of an organization. Users are therefor hidden and can not log them selves in. So they cannot flag themselves as 'attended' for a 'meeting'. Meeting is a content type.

The idea is that the administrator opens a 'meeting node' during the actual meeting and a list of all users is displayed beneath. Next to a user there should be a button 'Attended'. Clicking it should flag that user for this particular meeting node.

When the meeting is over (the next day) opening the meeting node should just list the attendees and non-attendees in a separate list beneath the node without the buttons.

I know of the signup module, but D7 work is still on its way, and i thought flags would be a good and simpler alternative. I just need to figure out a good way of getting the list of users beneath the node and flag them ...