Using dummy as an attachment point for handgun

A character and a handgun made in 3ds max. Character can put the pistol in the holster, he can take it in right hand, aim etc. In different situations pistol should be positioned very accurately. Is it ok to use dummy on the hand, another dummy on the holster, and another dummy on the pistol to specify the exact point where the gun should attach? I mean, I can't attach handgun to hand or holster directly, it should be aligned very accurately with very specific angle. Each pistol has different size and also should be positioned slightly different in the hand. The gun should not be absolutely parallel to hand bone because naturally you don't hold your hand aligned with your handgun, but slightly different angle. So, my idea is to use dummies to specify exactly the rotation and position of the handgun in hand. And you just attach pistol dummy to other dummy to follow the position and rotation angle. Is this idea possible in Unity? I mean 3ds max dummies. Is there any other better way for this?