animated object is moving against an animated object

Hello Folks,

I hope I'm in the right forum here, I just started getting into Unity...

I'm riging a model and the Idea is to have to animated obects moving against each other, so in case one obect as strong as the other one, they should remain in the same position, but once there is move power on one side, the object supposed to push the other against a wall or floor. But its not just an animation, it should be controlled by the player. By pushing a button many times per minute, the movement is either strong or weak, he wins or loses by pushing the controller button too fast or too slow...

The difficulty comes from not just having to static meshes moving against each other, which would be pure physics, but for example two creatures or people pushing against each other, and if one is stronger than the other, there is an axis towards which I expect the object to move.

supossed we have a man holding a box in his arms and if its too heavy the arms supposed to move downwards, but if you push a button many times, the arms supossed to lift the box upwards in small steps.

My question is > How do I manage such a sequence ? Is it a rigged animation triggered to gamecontroller commands ? Is there a concrete tutorial I can find out ?

It might be even something like this >

http://www.jtfo.de/uploads/pics/imago_ringen.jpg

how do I programm it into the unity engine, because just rigging movements is not enough, now the animation of my first object is influenced by the other, so the objects movement is changed by the other object...

Please look at the minute 4:50, then you know exactly what I mean

https://www.youtube.com/watch?v=y8OqZKbYBlE