if you really wanna do this, which i cant recommend (because it causes a disconnection between your actual hand movement and the percieved mesh which can feel really weird), you can disconnect the hand mesh comp from the motioncontroller and move it on tick to match up with the motioncontroller. If you wanna stop or override the hand transform, make a select and drive the transform from either the mc or some fixed point you want it to stay it. Hope that makes sense.
If you do this however, i would recommend, atleast to add in a ghost hand mesh that shows where your actual hands are.