Associating audio tracks with different groups?

[FallenAngelII]

I have no idea what this means or how to do it, but apparently I need to (in order to get alternate audio tracks to play on the iPod. Handbrake does it and tracks passed through Handbrake will play on iPod Classic with alternate audio tracks).

Preferrably through MP4Box but any program is fine as long as I can still encode my stuff through meGUI.

So how exactly do I do that? One of the developers for Handbrake tells me that I need to, and I quote:
"Are they being associated in an alternate group though?"
"it means the audio tracks need to include the alternate group property in their headers and set them to the same value"

So... how do I do this in, say, MP4Box (Gui or CLI, either way)?

[Baldrick]

One similar topic is enough. Continue in https://forum.videohelp.com/topic359011.html . Reply to add new information.