Ok that works. Slight correction: needed was xmodmap -e “keycode 77 = KP_F1”
Also can put lines like keycode 77 = KP_F1 in a file and invoke using
xmodmap <file-name>
Problem turned out that I was editing the player.cfg file on the server side instead of the client side. Now everything works as advertised. Thanks for your help!
Thanks for the answer but I am still confused. Does the free version (on Linux if it makes any difference) support virtual desktop functionality which allows individual multiple Linux desktops?