(defun skk-henkan-C- ()
  (concat "C-" (skk-henkan-ctrl-meta-conversion (read-string "C-"))))
(defun skk-henkan-M- ()
  (concat "M-" (skk-henkan-ctrl-meta-conversion (read-string "M-") 'meta)))
(defun skk-henkan-ctrl-meta-conversion (input &optional metap)
  (if (and metap (string= "x" (substring input 0 1)))
      input
    (replace-regexp-in-string
     "c-" "C-"
     (replace-regexp-in-string
      "m-" "M-"
      (replace-regexp-in-string
       "h-" "H-"
       (replace-regexp-in-string
        "ret" "RET"
        (replace-regexp-in-string
         "spc" "SPC"
         (replace-regexp-in-string
          "tab" "TAB"
          (replace-regexp-in-string
           "esc" "ESC"
           (replace-regexp-in-string
            "del" "DEL"
            input))))))))))
;;; (skk-henkan-M-)
;;; (skk-henkan-C-)