Encoding from MKV ordered chapters

I'm having trouble encoding MKV ordered chapters to .avi XviD (for DVD playback purposes), specifically the audio.

I can encode the video stream fine by using MeGUI since DirectShowSource uses Haali Media Splitter (thanks to the K-Lite codec tweak). The problem is I can't seem to get the audio of the ordered chapters to one stream and encode it.

I'm aware that this can be done using VirtualDub by using Avisynth's DirectShowSource with audio enabled, but I'm trying to avoid that method since there doesn't seem to be an automated 2pass in VirtualDub.

Are there any other methods/workarounds on this?

Thanks.

Edit : Also, if there are ways to extract the audio from ordered chapters into one stream, please do mention them.