Please check my answer before - I linked objects in ExtendedDictionary and allpy new position to all lined objects during move events.
Don't forget to handle copy/paste/delete for your objects it you want to store linked object list for copies objects for example.
Editor is easy - I have 2 promt dialogs - choose first object/point and choose linked object. And then I store this new link - I add new key/value in ExtendedDictionary as handle=linked_handle1, linked_handle2,... So I can easy parse it during any event.