Welcome, @Egon-Olsen, to the Notepad++ Community. You said:
As this key seems to be “not user-assignable”, it looks it is “internally hard coded” ?
Is there a reason for that ?
Unfortunately it does not work this way and when looking at the current shortcut config within NPP it shows “Ctrl+unlisted” / “confict found”.
Is there any possibility to get this realized ?
When I tried to set a shortcut using the Settings > Shortcut Mapper, the ^ caret key doesn’t even show up. I believe this is because ^ isn’t a separate key (on a standard US keyboard): it’s the Shift+6 key (US).
So if you want the keystroke to be Ctrl+^, that’s the same as Ctrl+Shift+6. That, you can easily map in the Shortcut Mapper, or by the following line in your shortcuts.xml:
<Shortcut id="43009" Ctrl="yes" Alt="no" Shift="yes" Key="54" />
(Remember that if you edit shortcuts.xml in Notepad++, you must not have changed any settings in the current session; the best advice is close all Notepad++ instances, open Notepad++ and edit shortcuts.xml; save and exit Notepad++; reload, and the change should take effect. But I find it easier to change in the Shortcut Mapper)
edit: or, as @Michael-Vincent posted while I was typing this, you could just use the Ctrl+6, if you don’t want to hit the extra shift key; I don’t know which you would prefer.