please try this in moodlelib.php file (location:lib/moodlelib.php).
with in this file, you can add some code in the following function : normalize_component
} else if (preg_match('/^(your part of lang file name)_/', $component)) {
$type = 'your part of lang file name';
$plugin = str_replace('(your part of lang file name)_', '', $component);
}