Excuse me for stating the obvious but whatever you do to your disc, it won't play in your hifi, or in any other standard CD player, only in a PC or DVD player.
With that in mind, you can rip the CDs to any common audio format such as mp3 or wav and then create a data disc (this is the jargon Nero will offer you - Nero is the software that many people use to save things to CD/DVD).
Much more than 3 CDs worth will fit if that's an issue at all.