You may need several utilities for that. I assume you want just the music and then convert it to MP3 or create a CD Audio for it.
First, you have to demux (or demultiplex) the vob file to get the audio. I used to use DVD2AVI for that
http://www.afterdawn.com/software/video_so...ers/dvd2avi.cfmOnce you got the audio, it will not be compatible with CD audio because its sampling rate is 48khz instead of 44.1khz. Thus, you need another utility to do this conversion. I used Sony Sound Forge for that, but almost any audio editor can do the job. Plus, you can use the audio editor to split the entire audio program into individual song and delete whatever you don't need.
And once you got the sampling frequency down to 44.1khz, you can use Nero to burn it into CD audio -- come to think of it, maybe Nero can even convert the 48Khz to 44.1Khz for you automatically, but I haven't try it though. Or you can convert it to MP3, WMA, ... using other converters.