Shortcut for common key commands in XFCE

Hi. I’m trying to change the keyboard shortcuts for subscript and superscript.

I’m aware of the shortcuts menu for opening applications in Settings→Keyboard. There’s also a shortcuts menu for things like resizing windows and the up, down, left, right arrow keys at Settings→Settings Manager→Window Manager→Keyboard.

I haven’t been able to find a shortcut menu for standard keyboard commands (cut, paste, subscript, superscript, etc.). Does such a menu exist? If not, is there some other way to alter these shortcuts?

I also tried to change the subscript/superscript in LibreOffice, just to see if it could be done on a program to program basis, but the modify key is greyed out for those commands (and not for others). That seems to indicate that subscript/superscript are global commands in XFCE which can’t be overridden, at least by LibreOffice.