Here is an shot of four frames that make up a walk cycle for the Mouse example object (included in the Motion Studio Library folder). We will use the PasteRegister function to extend this walk cycle.

If these frames are copied and pasted, the pasted frames would occupy the exact same position as the copied frames. But we want to extend the walk, not repeat it in place.
First, we notice that the toe-joint at the left foot of the character is planted at the beginning and the end of our walk cycle. Therefore we can use it as a reference point, or what we call the registration point.

We select that toe joint and click the Mark button (the buttons referred to here are on the DopeSheet).
Next, we select the walk cycle frames, and click Copy. Now, instead of regular Paste we will use PasteRegister. We select the frame where we want the pasted animation to go, and click PasteRegister. This command will paste the frames, and automatically use the Marked joint to line up the animation.

Now we can use PasteRegister over and over again. Each time, the pasted frames will extend the animation further.
Here we show the complete process:
