Title pretty much says all, it's basically a modded rotator/gun combo (or just create a mod that adds a munitionHeading/Distance/Elevation, munitionLongtitude/Latitude/Altitude, and/or triggerInput in case of guns value for Funky Trees) that automatically points at incoming missiles and engages them? It should be linked to 'Turret Groups' i.e. a turret group=a group of elevation rotators, transverse rotators, and guns that all engage missiles as a single unit, but otherwise multiple turrets would engage multiple missiles independently of each other and/or aircraft, on a priority list of closest to furtherest (munitions, however, are top priority, if a plane is closer to a ship than a missile, the CIWS should still aim for the missile rather than the plane).

There's this mod called 'Anti Missile Ball' that's pretty cool, but if the rotators(and guns) could be modded to behave more or less the same way, the possibilities would be endless.