Here is a bit of code borrowed from one of my other answers:

• Create a new scene

• Create a cylinder

• Scale the cylinder to (0.005, 1.0, 0.005)

• Put the following script on the cylinder

  ---

  pragma strict

  var pos1 : Vector3; var pos2 : Vector3; var objectHeight = 2.0; // 2.0 for a cylinder, 1.0 for a cube

  function Update () {

     if (Input.GetMouseButtonDown(0)) {
          pos1 = Vector3(Input.mousePosition.x, Input.mousePosition.y, Camera.main.nearClipPlane + 0.5);
           pos1 = Camera.main.ScreenToWorldPoint(pos1); 
           pos2 = pos1;
    
       }
    
       if (Input.GetMouseButton(0)) {
          pos2 = Vector3(Input.mousePosition.x, Input.mousePosition.y, Camera.main.nearClipPlane + 0.5);
           pos2 = Camera.main.ScreenToWorldPoint(pos2); 
    
       }
    
       if (pos2 != pos1) {
          var v3 = pos2 - pos1;
           transform.position = pos1 + (v3) / 2.0;
           transform.localScale.y = v3.magnitude/objectHeight;
           transform.rotation = Quaternion.FromToRotation(Vector3.up, v3);
       }
   }