I have a Swedish keyboard, and I can't write ?, ?, or ? in neither Morrowind or Oblivion.
Also, if I type "?" I get a "-", and if I type "-" I get a "?".
Well, you can use number combinations. If you hit num lock, hold down the left alt-button and type in the right number combination, the proper letters will appear.
These are the combinations for ?, ? and ?:
146 (?)
145 (?)
157 (?) or 153 (?)
155 (?) or 148 (?)
143 (?)
134 (?)
Edit: Only works with numbers on the numpad
Not the easiest way, but better than nothing...
DIdn't work.