int transpose_font(FONT *f, int drange)
   FONT *myfont;
   FONT *capitals;
   ...
   /* Create a font of only capital letters */
   capitals = extract_font_range(myfont, 'A', 'Z');
   
   /* Now transpose the characters in the font so that they will be used */
   /*  for the lower case letters a-z */
   transpose_font(capitals, 'a'-'A');
   textout_ex(screen, capitals, "allcaps",
              100, 100, makecol(255,255,255), 0);