The value is the "shift" value of part origin from the machine offset origin. Think of it as somewhat similar to G92/G52 except on a rotary axis. So, after you set a work offset to your center of rotation, you set the shift amount of how far your part sits "off center" of rotation. If you part sits at .003 to the left of center and everything else is on "zero", you would have a "-.003" in your X axis of dynamic comp...
As far as the command of using it, you only need have the offset show up like a standard work offset.
It's just a part..... cutter still goes round and round....