I tried on collision -> Player set vector Y 2000 for example, but it just doesn't cut it.
That should work. Please keep in mind that you are still bound to the parameters from the platform behavior. That means if your 'Max speed' is 60 an you would give an impulse with vector X, the speed would never go over 60 no matter of your value you set the vector X. The same with Max fall speed and Deceleration and other parameters.
Another point is that VectorY = 2000 would give an impulse to the bottom. If you want an impulse up you have to use -2000 (The upper left corner is 0,0 in coordinates)