scratch buffer

(define-key-after
  global-map
  [menu-bar bertl]
  (cons "Bertl" (make-sparse-keymap "beidel"))
  'tools)

(defun bertl-pipe-region (command)
  (interactive "sCommand: ")
  (shell-command-on-region (region-beginning) (region-end) command nil t))

(define-key
  global-map
  [menu-bar bertl pipe-region]
  '("Pipe Region" . bertl-pipe-region))