You can do something like –
(layer’s position property)
L = thisComp.layer(“Null 1”); // rename for your null
L.transform.position;
(rotation)
L = thisComp.layer(“Null 1”);
L.transform.rotation;
etc.
But then you’d need to add extra complexity to it to handle the switchover – and if the nulls are in different positions the layer would jump.
A better solution might be to parent Null 2 to Null 1, and the layer to Null 2. Then just move one null at once.