Move a Camera with a Data from a Text file after Build.

Hello.

I try to move camera with a data from a text file after build. there is a text file which is refreshed while the unity 3d program is running. And I want to read the text file and use a data in it to move a camera.

I found some information about it and made a code for testing.

 using UnityEngine;
 using System.Collections;
 using System.IO;
 
 public class CameraController : MonoBehaviour {
 
     public TextAsset textFile;
     string tmps;
     StringReader read = null;
 
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         transform.Translate (new Vector3 (0, 0, 1) * Time.deltaTime);
         textFile = (TextAsset)Resources.Load ("/test.txt");
         read = new StringReader (textFile.text);
         if (read == null) {
             GetComponent<TextMesh>().text ="not found";
         } else {
             tmps = read.ReadLine ();
             GetComponent<TextMesh>().text = tmps;
         }
     }
 }

There is a error: NullReferenceException: Object reference not set to an instance of an object CameraController.Update () (at Assets/Scripts/CameraController.cs:20)

I heard that this way is using text file in MyProject_Data/Resources after build. But I don't know that I understood it well.

What is the way to do this? Is this code right?