(defun my-open-file-external (program file-names &optional args)
  (let ((file-names-as-string
         ;; (mapconcat '(lambda (file) (concat "\"" file "\"")) file-names " ")
         (mapconcat 'identity file-names " ")
         ))
    (start-process (file-name-nondirectory program) nil program file-names-as-string (or args ""))
    ))