Configure bootup disk as follows:

DEVICE=HIMEM.SYS, DEVICE=RAMBODSK.EXE /F=720 added to CONFIG.SYS. If they don't have DDPro, use VDISK.SYS instead.

Copy Rambodisk.exe and DISKDUPE.* from DD disk to boot up disk.

Modified AUTOEXEC.BAT to copy DISKDUPE.* and COMMAND.COM to C:, SET COMSPEC=C:\COMMAND.COM then change to C:.

Then run DiskDupe from C:, set it up the way they like it and then copy DISKDUPE.DAT back to the floppy.