how to load a o/s without a cd drive

One options I can think of is, if you remove the hard drive from the machine. Then they sell these cable where you can plug any hard drive into a USB port. Example here:

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1871517&CatId=470

You can pick these up at places like micro center and fry's. Then plug the hard drive into another machine, create a folder (not named windows) and copy the entire contents of the cd to the hard drive. Then install it back into the laptop and boot from a windows 98 boot disk and this will get you into DOS. Then just navigate to the folder with the CD contents and run setup. This is the best I can think of. Someone else might have a better idea.

Thinkpad 240 is quite an old machine. What OS do you plan on loading? You may need to get floppy version of Win98.

If you're installing XP, i think the floppy disks downloadable from MS will load the neccessary drivers for the rom drive, then hand off the install to the cd version

Could always try Linux