Syntax:  BOX UPPERCASE

  Changes the case of the text in the currently selected box.

  This command changes the case of the text in the currently selected
  box.  The diagonally opposite corners of the box are given by the
  beginning and end positions of the current selection.

  RELATED COMMANDS:

     BOX COPY                    BOX LOWERCASE
     BOX CUT                     BOX PASTE
     BOX CUT PAD                 BOX PASTE OVERSTRIKE
     BOX DRAW                    SET CLIPBOARD