This can probably be accomplished by a Move Cameria Button with explicit pixel coordinates, or by adding an invisible piece (in a low Game Piece Layers with traits Does not stack with no movement or selection, Restricted Access to make sure no one can manipulate it, and a unique name - say MoscowLocation), and a Move Cameria Button that moves to that piece.
You could implement it by Creating Custom Classes - in particular a custom BasicCommandEncoder and a custom Immobilized classes.
But, you can probably achieve the same effect by a Dynamic Property that sets the property NON_MOVABLE to true when the piece cannot be moved, and to false when it can. I haven’t tried that, but as far as I can tell, it should work. Of course, you should be careful if you mix that with the Does not stack trait.
Yours,
Christian