Media Library per user

Hi,

I’v made user registration on fronted, all custom no plugins and profile etc.

When user registers, folder is created for him. In this folder i want to put his images avatar and stuff.

In his profile, i got edit profile, and like a small dashboard where he can insert posts.

He insert posts trough tinymce, and there is Add Media Button.

What i need is to point this add media button, to his folder, so he can only see / edit his own images ( name of the folder is in User meta ).

How can i do this?

Thanks, il post my wp_editor code here :

$args = array(
    'textarea_name'=>'contentarea',
    'textarea_rows' => 15,
    'teeny' => true,
    'quicktags' => false
);
 wp_editor( 'This is the default text!', 'editor', $args );