hook_permission and control access [how to redirec

How does one limit "what" can access a page. I have little understanding on how to use hook_permission() to set user permission based on a role to control access to hook_menu() items. However, what if I have a hook_menu() item that is to be used solely by the system itself? For example, say I have a registration page in a custom module: module/register - Anyone can access that page. Then, say I have an another page which is only for admin. So, I register another item in hook_menu(), call it module/register/reg_user_details - I do not want anyone to be able to browse to module/register/reg_user_details

Instead I want page to be visible only when user is logged in, I have already created a hook_permission

/**
 * Implements hook_menu()
 * 
 */ 
function video_subtitles_menu() {
  $items = array();
  $items['video_subtitles/upload'] = array( //this creates a URL that will call this form at "video_subtitles_test/upload"
    'title' => 'Upload Subtitle', //page title
    'description' => 'Uploading subtitle for videos',
    'page callback' => 'drupal_get_form', //this is the function that will be called when the page is accessed.  for a form, drupal_get_form need to be used 
    'page arguments' => array('video_upload_subtitles_form'), //Name of the Uplaod Form 
    'access callback' => 'user_access',
    'access arguments' => array('administer video_subtitles module'),
  );

  $items['player/video_subtitle_status'] = array(
     'page callback' => 'video_subtitle_status',
     'access callback' => 'user_access',
     'access arguments' => array('administer video_subtitles status'),
  );
  return $items;
}

/**
 * Implements hook_permission.
 */
function video_subtitles_permission() {
  return array(
    'administer video_subtitles module' => array(
      'title' => t('Administer video_subtitles module'),
      'description' => t('Access the video_subtitles upload module Page'),
     ),
    'administer video_subtitles status' => array(
      'title' => t('Administer video_subtitles module status'),
      'description' => t('Access the video_subtitles module status Page'),
  ));
}

So User is not able to access my page unless user is logged in, but what I need user should be redirected to the login page when he is not logged in as admin , if he successfully login it should be redirected to my page.