Titanium: Note, however, that some of these don't work under DosBox. Ctrl-F1, for instance, pops up some options for DosBox.
Conveniently, that option screen is the keymapper screen for DosBox.
So to get rid of it and to allow the Darklands functionality, you only have to do the following:
(Note: Instruction only aimed at those who just want the leader quickchange to work and do not need something remapped.)
1. "Ctrl + F1" (opens up the keymapper)
2. "Click on Mapper"
3. "Click on Del"
-- If you want to be able to quick-change to your fifth (the NPC) character, you might also want to do the following before step 4 --
3a. "Click on Screenshot"
3b. "Click on Del"
--
4. "Click on Save"
5. "Click on Exit"
Edit:
I noticed that on my system DosBox likes to crash to desktop after exitting the keymapper. Not to worry, though. The changes will have been saved and the instruction works.