Solution #1.
Leave the figures on the ground, apply the poses. Load a Poser square primitive, make it invisible, parent both figures to the primitive (from the menu bar, Figure > Set Figure Parent). Raise the primitive until the figures are level with the ring.

Solution #2.
Most poses don't contain translation data for the Body actor. If that is so in your case, you can just yTran the Body until it is at the correct hight.

Solution #3.
In frame one, lower the ring until it is level with the ground. Hide the ground plain, and use a scaled Poser one sided square as a false ground.