I want to make use of a Thinkpad trackpoint's thumb buttons which I almost never use in Emacs anyway. I'd like to use them as additional
Controls in Emacs, and in Emacs only. I've found this answer, where it is pointed out that it may be possible to do just so:
One obstacle for a full equivalent to Control is that it would need to know both when it was held down and when it was released. Emacs keyboard events (unlike mouse events) don't get split into 'down' and 'up' parts, which makes 'released' hard for us to detect there.
However there were no example given and being an absolute beginner in Emacs Lisp I'm not quite sure what to do with it.