not quite sure what submounting is....
Im not quite sure what submounting is... but you only need to mount your floppy when you insert it into the drive... and right before you take it out... nothing more than that really...
if you have a floppy drive icon right on your kde desktop this is quite easy
simply right clicking on the icon will present you with a mount/unmount command in the menu.
If you do not have a floppy drive icon you can add one by right clicking on the desktop and goto new... there you should see floppy device or removable device etc... the rest should be pretty strait forward.
good luck to you - burnt-toast