I presume that you have installed a new hard disk drive… You say the CD-ROM drive in the Thinkpad "may" not work. Have you tried booting the recovery CD with it or accessing it with a Windows startup floppy (http://duxcw.com/digest/Fromshop/software/windows/startup/startup.htm). The drive has an ATAPI IDE interface and, if it works, is probably accessible with the default drivers on a startup floppy I see no DOS (real mode drivers) for the PCMCIA interface on IBM’s site.
This bit of info from HP’s site might help, but I doubt it:
QUESTION: How do I get the latest drivers for my external PCMCIA CD-Writer?
ANSWER: The external PCMCIA CD-Writer uses Windows PCMCIA drivers, and the driver files provided on the floppy diskette that shipped with the drive. These driver files also reside in the Resource directory on the Installation CD. If the original floppy diskette is lost or damaged, the CopyDisk Utility that resides on the Installation CD can create a duplicate. Find the CopyDisk Directory and launch the CopyDisk.exe program. Follow the instructions to create a Driver Install floppy diskette. At this time there are no updates to these drivers.