I am using Unity3D to move the player around the circumference of a large circle facing inwards towards the centre at all times.

The following code works by using transform.forward

  // Rotate the forward vector towards the target direction
    Vector3 newDirection = Vector3.RotateTowards(transform.forward, targetDirection, singleStep, 0.0f);

and then I move the player sideways by using

characterController.Move(horizontalSpeed * transform.right * Time.deltaTime);

I have been stuck on how to get the player to move around the circumference but facing forward with the left of the player facing the centre of the circle. My code is as follows

   void Start()
    {
        characterController = GetComponent<CharacterController>();

    }

    void Update()
    {


        // Determine which direction to rotate towards
        Vector3 targetDirection = GameObject.Find("Platforms").transform.position - transform.position;

        // The step size is equal to speed times frame time.
        float singleStep = 1 * Time.deltaTime;

        // Rotate the forward vector towards the target direction by one step
        Vector3 newDirection = Vector3.RotateTowards(transform.forward, targetDirection, singleStep, 0.0f);

        // Draw a ray pointing at our target in
        Debug.DrawRay(transform.position, newDirection*50, Color.red);

        // Calculate a rotation a step closer to the target and applies rotation to this object
        transform.rotation = Quaternion.LookRotation(newDirection);

        CheckIfOnGround();

        characterController.Move(velocity * Time.deltaTime);

    }