Add custom_post_type menu into existing menu

{code type=php}

add_action( ‘init’, ‘premem_create_post_type’ );
function premem_create_post_type() {
$labels = array(
‘name’ => _x(‘Premium Content’, ‘post type general name’)
);

$supports = array(‘title’, ‘editor’, ‘thumbnail’);

register_post_type( ‘premium’,
array(
‘show_ui’ => true,
‘show_in_menu’ => ‘wp-premem-membership’,
‘labels’ => $labels,
‘menu_position’ => 5,
‘public’ => true,
‘supports’ => $supports
)
);
}

{/code}