Grendizer : in case your answer to my previous question is negative I might have a solution for you, but I have to warn you : it's not a pretty one :D
I want to trap your keypresses by another application called Girder.
(Girder is a very powerful tool, mainly used by people with remote controls, but it's far more powerful than that).
In this first part I would like you to test if Girder is able to understand your special keys. If it does, I will explain you how to control BSplayer with them.
First download a trail version of Girder from the official website :
http://www.promixis.com/downloads.php?mode=trials
Install it and run it.
(I'm still using an old version so I hope the menus are the same)
Goto "file/settings/plugins" and check the box next to "keyboard".
Exit Girder (make sure it didn't minimize to the system tray)
Restart Girder.
Goto "File/Enable input devices"
The blue circle at the bottom right should now have turned green.
Now press one of your special keys.
Does the green circle turn yellow for a short time?
Is there a hex number on the left of the circle ?
Is that number always the same when you press the same button?
Is it different when you press another one?
If your answer to all of these questions is "yes", you are able to control BSplayer with Girder and I will explain that in part 2 :D
Good luck,
Rafke P.