how to apply multiple Functionality like touch moves with Buttons move..?

i am confused i would like to create Character that already moves with the button touch ..So My Question is How to Moves Camera with the Touch screen up and down? Is It Possible to works Both Functionality button moves character and touch moves Gun point???? It would be rude to ask for the hole script so I just want some hints or tips because I am a beginner and I want to learn on my own. So please if anyone could help me I would really apreciate it.

please help me i need just Guidance please Thanks you So much For Advance.

 var walkSpeed : float=15;

 private var Controller : CharacterController;

 private var motion: Vector3;

 function Start () {
 Controller=GetComponent(CharacterController);
 
  }

  function Update () {
    if(Input.GetKeyDown(KeyCode.Escape))
    {
             Application.Quit();
    }
  }

  function Left()
  {
    motion=transform.TransformDirection(Vector3.left)*walkSpeed*Time.smoothDeltaTime;
     Controller.Move(motion);
  }

  function Right()
  {
       motion=transform.TransformDirection(Vector3.left)*walkSpeed*Time.smoothDeltaTime*-1;
      Controller.Move(motion);
  }

  function Up()
  {   motion=transform.TransformDirection(Vector3.forward)*walkSpeed*Time.smoothDeltaTime;
      Controller.Move(motion);
  }

  function Down()
  {
     motion=transform.TransformDirection(Vector3.forward)*walkSpeed*Time.smoothDeltaTime*-1;
    Controller.Move(motion);
  }