The spiritual weapon has 100'ft + 10'ft per CL distance to direct it. It hits like melee attack but works otherwise like a spell (it cannot be destroyed by mundane means as it's entirely made from magical force). So yes, I hit the fireball maid from +100'ft away with a spell which hits like a truck in melee combat. It targets her normal melee AC. If there is miss chance because incorporeal the hammer (or dildo) ignores it.