Ah, tnx i get it. Tnx for the reply ! Im looking more for something more easy and less damging to my cases. As in, unscrewing evry time i need the case, thats gonna make some damage.

-- Gijsja

in your first post you said ...i dont mind drilling in yhe cases...
the "damage" would be 2 holes on each case edge that has to be connected (a total of 8 holes)
attaching and removing a metric screw within a metric nut does not cause any further damage.