Sorry if I'm not providing much on this. I'm starting from scratch and a bit
lost.

I have a spreadsheet that has a list of users on it. Next to each user I
have added an "In Attendance" field with check boxes. A field has a point
total in it. When users attend certain parts of an event, they earn points,
which are added to the point total field. The things that earn points can
happen quickly and attendance can change throughout the event.

What I want to do is add a button to the spreadsheet that, when clicked,
adds say five points to each user with the "In Attendance" check box checked.

I'm not asking someone to make this for me, but I'm not even sure where to
go to look up something like this. Has anyone done anything similar? If so,
any help would be appreciated.