Animation / Distance

Hello! Quick question.

I want my characters animation to be in-line with the distance to a certain position.

The starting point of the Animation will start from starting position and the end of the animation will be when the character reaches his/her destination.

Easy Example: A leap through the air. Starting point initial take off // Middle: mid flail // Position reached: ready to land

I have all the animations I am just confused how to go about this (java scripting).