Execute Emacs Lisp in org file when it's opened.

gistfile1.txt

(setq my-org-init-elisp-beg "# elisp")
(setq my-org-init-elisp-end "# end")
(setq my-org-init-elisp-comment "^#")

(defun my-org-init-elisp ()
  (save-excursion
    (goto-char (point-min))
    (while (re-search-forward my-org-init-elisp-beg nil t)
      (let ($beg $end $elisp)
        (forward-line 1)
        (setq $beg (match-end 0))
        (when (re-search-forward my-org-init-elisp-end nil t)
          (setq $end (match-beginning 0))
          (goto-char $beg)
          (while (re-search-forward my-org-init-elisp-comment $end t)
            (setq $elisp (cons (buffer-substring-no-properties
                                (match-end 0) (min (1+ (point-at-eol)) $end))
                               $elisp)))
          (eval (read (concat "(progn" (apply 'concat (nreverse $elisp)) ")"))))))))

(add-hook 'org-mode-hook 'my-org-init-elisp)


;; Example
;; Write elisp like below in your org file
# elisp
# (highlight-regexp "elisp" 'hi-green)
# (highlight-regexp "high" 'hi-ping)
# (highlight-regexp
#  "end"
#  'warning)
# end