P.S. I forgot to mention. For Solution #1 you should use Linear interpolation on the primitive, and set key frames as appropriate, in In Solution #2 you should use Linear interpolation on the yTran channel of the Body, and set key frames as appropriate.

Solution #4 (requires P6 or above).

Save the attached file to a pose folder. Remove the ".TXT" part of the file extension.  You may need to change your Windows Folder options so that it does not hide file extensions. In Windows Control Panel, Folder Options, view tab, un-tick "Hide file extensions for known file types".

Apply the pose to your figures. You should find two new dials in the Body actor.

"Altitude_STATIC". You can use this dial to apply a correction factor to the altitude (yTran) of the Body actor. The channel is static, meaning that what ever you set it to, in which ever frame you set ti, it will maintain that setting throughout all frames of the animation. It works the same as when you turn off animating for a light or camera.

"Altitude_DYNAMIC". This works like an extra normal yTran dial (not static), so you can adjust the yTran independently of any yTran that a pose may be applying to the Body actor.

After applying this pose, you should not attempt to move the Body actor by dragging with the cursor in the document window, as you would get strange results. Instead, move it via the dials in parameters pallet only (it's OK to drag the hip).