Ok, solution for those who might find this making an Internet search: Finally the easiest way is to remap indeed a physical key to the generic Windows "Pause" function, as [NAME] suggested further up. I used for this the suggested "PowerToys Keyboard Manager", since it's quite user--friendly (less opportunities to brick my computer...). Now the problem is I don't have unused hardware keys I could spare, and I'm not rich enough to dedicate a 3000 € laptop to a single game, so I got me a cheap external USB Numpad, and mapped a key of that one. "PowerToys Keyboard Manager" had no problem detecting its keypresses. As for the "Pause", the program allowed me to just select the generic "Pause" function, and despite "PowerToys Keyboard Manager" complaining this isn't valid, it does work! Thanks to all involved.
My keyboard hides the "Pause" key under a Function (Fn+key).  Please, does anybody know of a way to remap or otherwise recreate the Pause key on Windows 11? How can one imagine creating a so called "Gamer's Laptop" which overheats with 5 year old games and which lacks something as basic as a "Pause" key?  
x17 R2, need "Pause" key for a game