Um... I posted this in some other guys topic that asked a similar question mentioning the in_cube plug-in. I guess you don't remember.
Or maybe I don't read every single topic in this forum? >_>
@Cat: Uh... I don't think so. Not that way, anyway. The vgmstream plug-in only works with Winamp. However, there is a manual method.
Grab Androu's tool and copy everything in the Tools folder to a new folder along with the brstm you want to convert (or just put the brstm in the Tools folder). Copy the two files in the other folder named "Copy these files to your system folder" to your System32 folder (you'll need admin powers to do this).
Now go into the new folder and run command prompt (there should be a shortcut in there).
Enter this line: revb.exe --extract songname.brstm name.dsp nameR.dsp
This will create two dsp files from the brstm with whatever names you enter.
Now enter this: dspadpcm.exe -d name.dsp
This will get you a wav file with the same name as the dsp. Do it again, but with nameR instead of name.
You will have two wav files, one of the left channel and one of the right channel. Open both in Audacity or Goldwave or whatever and combine them into one stereo file.