How do you add a 2nd audio track to a MP4 (h.264) movie?

[Mildew]

Both Handbrake and D-Vision will allow you to automatically add a second audio (commentary) track to h.264 MP4 when encoding from a different format. ffmpegX doesn't appear to have this option, although it does support adding a second audio track to an AVI (albeit in a roundabout method).

Is there a way to add a second audio track to a MP4 in ffmpegX?

[edoud]

Hi!
I allready ask this question and major's answer was :
" For now you can only put one soundtrack in MP4, but I plan to add MP4 support to the mux tool so as to enable multiple audio tracks."