how to simulate keyboard left right keys to touch button in unity 4.6 ?

torqueDir = Input.GetAxis ("Horizontal");

if (torqueDir != 0) {

         rigidbody2D.AddTorque (3 * Mathf.PI * torqueDir, ForceMode2D.Force);
     } else {
         rigidbody2D.AddTorque (0);
     }
     
     slope = transform.localEulerAngles.z;
     
     //convert the slope values greater than 180 to a negative value so as to add motor speed 
     //based on the slope angle
     if (slope >= 180)
         slope = slope - 360;
     //    dir = Input.GetAxis ("Horizontal"); 
     Debug.Log (dir);
     
     if (dir != 0)
         //add speed accordingly
         motorBack.motorSpeed = Mathf.Clamp (motorBack.motorSpeed - (dir * accelerationRate - gravity * Mathf.Sin ((slope * Mathf.PI) / 180) * 80) * Time.deltaTime, maxFwdSpeed, maxBwdSpeed);
     //if no input and car is moving forward or no input and car is stagnant and is on an inclined plane with negative slope
     if ((dir == 0 && motorBack.motorSpeed < 0) || (dir == 0 && motorBack.motorSpeed == 0 && slope < 0)) {
         //decelerate the car while adding the speed if the car is on an inclined plane
         motorBack.motorSpeed = Mathf.Clamp (motorBack.motorSpeed - (decelerationRate - gravity * Mathf.Sin ((slope * Mathf.PI) / 180) * 80) * Time.deltaTime, maxFwdSpeed, 0);
     }
     //if no input and car is moving backward or no input and car is stagnant and is on an inclined plane with positive slope
     else if ((dir == 0 && motorBack.motorSpeed > 0) || (dir == 0 && motorBack.motorSpeed == 0 && slope > 0)) {
         //decelerate the car while adding the speed if the car is on an inclined plane
         motorBack.motorSpeed = Mathf.Clamp (motorBack.motorSpeed - (-decelerationRate - gravity * Mathf.Sin ((slope * Mathf.PI) / 180) * 80) * Time.deltaTime, 0, maxBwdSpeed);
     }

"""this is a part of code it uses the keyboard horizontal axis to determine left and right input, i want to map the keys to the touch button on android in new ui 4.6"""