@Dandy
Had to take a look at the picture and read it again to get it. The Menu key can be changed from F12 to F11, Left Ctrl or Left Alt... it doesn't change the key layout just what key activates the menu. Seeing that the Amiga doesn't have the Right Ctrl I guess the only option is Left Alt unless you actually go in and change the keyboard layout of the underlying OS. Played around with SharpKeys (for Windows) myself for a simular thing, don't know what you'll need though.