Laplink is a small program (DOS version fits on bootable floppy disk) that allows you to copy files from one PC to another via the parallel port.
This requires a special 'laplink' cable which may not be that easy to get hold of these days, I don't know.
Dos version will obviously truncate long file names during the transfer but this isn't an issue for 98 OS cab files.
Another way of doing this, is to buy a 2.5 inch USB drive caddy. This will let you connect the laptops drive straight to the desktop, so you can see the laptop drive in windows from the desktop system.