Hoping someone can point me in the right direction. I'd like to add the ability to use a hand shower to our whirlpool tub. The current spout has a circular piece of metal which contains a washer and screen (similiar to that on a kitchen faucet. Is there a company that sells a diverter that will will thread into the female faucet hole and allow one to hook up a hand shower? I've seen them for showers but they are normally they just screw on to the existing shower head.

Sorry I don't know the "technical terms" for plumbing fixtures which might explain my inability to find what I"m looking for.

Thank You