Thank you for the quick reply, I really appreciate it!
I have to say, Flirc is a brilliant idea and I was thrilled when I found it. Its a very elegant and simple solution.
I just tried the command line you suggested, unfortunately it does the same thing as when using the + button in the GUI "full keyboard" controller (the button that has + when shifted and = when not shifted). When VLC is playing a video, pressing the + key on the numeric keypad speeds up the video, but pressing the + key on the main keyboard (with or without the shift key) is always treated as the = key by VLC.
Another way I can tell the + key on the numeric keypad is a different code than the + key on the main keyboard (+ and = key): when I open Properties for a Windows shortcut and go to the Shortcut key field and I hit the + key on the numeric keypad, the Shortcut Key field displays "Num +" whereas if I hit the + key on the main keyboard (+ and =) with or without the shift key, the Shortcut Key field displays "Ctrl + Alt + ="
I hope all this makes some sense!