Adjusting volume of dual audio tracks

[OmniGodBoy]

I'm playing a file with dual audio tracks (one is the regular audio, the other is commentary). I want to play both tracks simultaneously, but the commentary track is way louder than the regular audio track. How can I adjust the volume of the tracks individually so I'm not turning my volume knob every 2 seconds so that I can hear everything without going deaf?

[Rémi Denis-Courmont]

There's no support for that at this point.