Change plid of existing administration menu items
If you want your own top level admin menu group, you should probably create your own parent menu item and section there using hook_menu

e.g admin/website and put your menu items under that.

/**
 * Implements hook_menu
 */
function my_module_menu(){

  $items = array();

  // Provide own admin configuration menu section
  // using system_admin_menu_block_page for item groups
  // Top level section
  $items['admin/website'] = array(
    'title' =&gt; 'Website', 
    'description' =&gt; 'Local website configuration.', 
    'page callback' =&gt; 'system_admin_menu_block_page', 
    'access arguments' =&gt; array('access administration pages'), 
    'file path' =&gt; drupal_get_path('module', 'system'),
    'file' =&gt; 'system.admin.inc',
  );
  // Child admin menu group
  $items['admin/website/config'] = array(
    'title' =&gt; 'Configuration',
    'description' =&gt; 'Configure website settings.',
    'page callback' =&gt; 'system_admin_menu_block_page',
    'access arguments' =&gt; array('access administration pages'),
    'type' =&gt; MENU_NORMAL_ITEM,
    'weight' =&gt; 50,
    'file path' =&gt; drupal_get_path('module', 'system'),
    'file' =&gt; 'system.admin.inc',
  );
  // Child group menu item
  $items['admin/website/config/advanced'] = array(
    'title' =&gt; 'Advanced settings',
    'description' =&gt; 'Configure advanced website settings.',
    'page callback' =&gt; 'drupal_get_form',
    'page arguments' =&gt; array('mymodule_website_settings_form'),
    'access arguments' =&gt; array('administer site configuration'),
    'type' =&gt; MENU_NORMAL_ITEM,
    'file' =&gt; 'includes/my_module.admin.inc',
  );

  return $items;

}


See system_menu for an example hook_menu using system_admin_menu_block_page