I've done it a couple of times -- most 'external' drives are actually internals with their own power supply. Just take the external enclosure apart, and remove the drive.

Pioneer Electronics Inc. on Monday announced that the DVR-S606, a new multiple format external DVD/CD writer, will be available in mid-September. The drive — which will have a suggested retail price ...

Are you sure it's a parallel cd recorder? IME Most external CDRs are SCSI. If it is parallel, you could probably use a switch box. If it's SCSI you'll need a SCSI adapter.