This will dismantle that wall of motion captured key frames into something more manageable. It’s not the most sophisticated of algorithms. But, it gets the job done and leaves you with nicely lined up key-poses. To use simply:

Quick copy and paste Biped animation to another biped from one instance of max and paste them into another.

History:
Copy/Paste Biped Animation V 1.0
- Main idea Tools.
- macroscript file.

Updated :
Copy/Paste Biped Animation V 2.0
- Added some option for copy or paste.
- Added paste replace or merge bip motion as option.

This script was made to retarget animations so that changes could be made to the biped's proportions throughout production.

I made this for making my life easier between Max and Unity (though it could be used in any max-based pipeline). Unfortunately Unity has no native retargeting, unless your team is using Mecanim.

Copies horizontal position of the biped onto the root object and links the biped to the root.

Two useful uses for this script:

1. Use it to create a root for your biped (using the Static Root option) - so you can place your biped with animation anywhere in the scene without adding extra keyframes. Simply move the root instead of the biped itself.
2. Some game engines require a moving root to calculate biped's position in the game environment space. With a moving root the biped itself actually stays in place and only the root moves.