I'm sorry, but if you want to convert those to CDG format, I'm afraid, it is not possible. You should be able to strip the audio track off the MPEG files located on the disc (the extension is DAT, so you need to change it to MPEG to play the files on the computer), but we do not have any software for that.
Change its extension from DAT to MPG, and you will get a video file. You will then need to find the software that will allow you to strip the soundtrack from video file, and save it as WAV.
If you get the virtualdub program, I can help you with the setup. I converted my VCD Karaoke tracks to avi files and they play great on the karaoke pro player