How to set default touch position roblox studio

So as most may know, when using mouse.hit.p on pc its works just fine, and on mobile it get the spot the player pressed last on the screen. But i want to know how i can make it so that tap position is always in the middle of the screen, kind of like shift lock. I made the shift lock for mobile, but i still want it to act as a aiming device, and not get the last position the player touched on the screen.