Problem with metadata.php and new class

Hello,

sorry but I obviously havn't quite understood how to make a new class and add it to metadata.php

I'd like to have a new submenu in admin calling cl=articleimport

So it's a new class and I wouldn't use 'extend' in the metadata.php, right?
Do I have to use 'files'?

I have now two files (not in the modules-path up to now):

1) application/controllers/admin/articleimport_main.php
class Articleimport_Main extends oxAdminDetails
{
.
.
.
}

2) application/controllers/admin/articleimport.php
class Articleimport extends Articleimport_Main
{
/**
* Current class template name.
* @var string
*/
protected $_sThisTemplate = 'articleimport_main.tpl';
}


My new modules path would be:
'articleimport/application/controllers/admin/articleimport/articleimport_main.php'

So how would I write the metadata.php?

Would be great to get your hints :)
Thanks,
Poko