Add sub menu to hard coded menu item

I added some hard coded menu items for login & logout and profile, now i want to add a sub menu to profile menu item.
This is the code i have:

add_filter('wp_nav_menu_items', 'add_register_link', 10, 2);
function add_register_link($items, $args) {

        ob_start();
        wp_register('');
        $registerlink = ob_get_contents();
        ob_end_clean();
        $items .= '<div class="menulogin">'. $registerlink .'</div>';
    return $items;
}

add_action( 'register' , 'register_replacement' );
function register_replacement( $link ){
	if ( ! is_user_logged_in() ) {
		if ( get_option('users_can_register') )
			$link = $before . '<a href="' . site_url('wp-login.php?action=register', 'login') . '">' . __('Register') . '</a>' . $after;
		else
			$link = '';
	} else {
		$link = $before . '<a href="' . admin_url() . '">' . __('My Account') . '</a>' . $after;
    }
	return $link;
}

I want to add a sub menu to My Account menu item, how can I accomplish that?

[ Please do not bump, that’s not permitted here. ]