You are trying to create a game playable for touchscreen, but you don't understand how..
I could do it fior you, but for me also it would consist of a lot of trying, albeit with a little more background information..
You are going to have to read up on touchID, for without it multitouch is impossible to implement..
you could add conditions if touch.x=0 and touch.y=0 and tell the character at what angle to hold the gun.
you could also add a condition if touch.y> a certain value to not point the gun there..
But the more difficult part will be the multitouch and working with the touchID..
It's been a while since I did that and I must say I've forgotten most..
I used it in my Thumbstick example:
Maybe looking how I did it there could help you..