addin meta-box to the attachment edit-page

Hello Forum,

I try to add a meta box (a checkbox) to the media edit-page.
My first idea was, to use the same function, I use for adding meta-boxes to other post-types.
But I’ve got two problems.
1. Where to hook the function, to call the add_meta_box() function.
I tried admin-init, and this works so far, that I get the datas in the global $wp_meta_boxes variable.
2. What do I pass as page-parameter of add_meta_box().
As I understand, the string given to the function has to match the slug, I get in the url after post.php, but attachments are edited via media.php. So add_meta_box() will never be called.

Now I wonder, if there is any way, to display a check-box at the media-page.

To save the input, I will try to use the same functions, I use for ‘normal’ meta-values I get if I use custom-fields at the attachment page.

Greets Paka