For many reasons I can't use a single object with 100 frames or animations, so I have to work on 100 different object unfortunately.
Why not? And why can't you combine them into a family?
It's not a good project organization when you have 100 similar but different objects, each with its own instance variables, behaviors etc.
Even if you find a way to run an event for all of them (say, via a script), working with these objects will be very-very difficult. I strongly suggest to reconsider.