WTH?
There is a specific track that plays when you fight certain enemies such as firrkraag, kangaxx etc that is missing from the soundtrack commonly found around the net and even I think on the official release ( DONT GIVE ME CRAP ABOUT THIS I OWN THE GAME + TOB ).
But you can go to myspace and enter "baldurs gate ii" and one of the myspace musicpages has it entitled "dragonbattlescore.mp3" so where do u find this without having to rip it from the game yourself??
BG2 Soundtrack MISSING dragon battlescore?
Take a deep breath... 
I found [url="http://www.3ddownloads.com/forge/forgottenwars/audio/BG2Music.zip"]this[/url] - although I haven't downloaded it, so I don't know if it contains the file you're looking for.
If it doesn't have the file, then it's entirely possible that the guy at myspace ripped it from the game files and converted it to mp3 himself.
Have you tried saving the mp3 file from myspace? Or contacting whoever made the page?
There is an editor tool for converting the audio files from IE games to WAV (which you can then convert to mp3 with your regular audio convertor).
It's called acm2wav and you can download it [url="http://www.sorcerers.net/Games/dl.php?s=IEM&f=IEmodding/acm2wav.zip"]here[/url].
See the attached tutorial.
I found [url="http://www.3ddownloads.com/forge/forgottenwars/audio/BG2Music.zip"]this[/url] - although I haven't downloaded it, so I don't know if it contains the file you're looking for.
If it doesn't have the file, then it's entirely possible that the guy at myspace ripped it from the game files and converted it to mp3 himself.
Have you tried saving the mp3 file from myspace? Or contacting whoever made the page?
There is an editor tool for converting the audio files from IE games to WAV (which you can then convert to mp3 with your regular audio convertor).
It's called acm2wav and you can download it [url="http://www.sorcerers.net/Games/dl.php?s=IEM&f=IEmodding/acm2wav.zip"]here[/url].
See the attached tutorial.