(defun sacha/emacs-wiki-markup-string (string)
  "Mark up STRING according to `emacs-wiki-publishing-rules'.
No header or footer is added."
  (let ((emacs-wiki-project emacs-wiki-current-project))
    (with-temp-buffer
      (emacs-wiki-mode)
      (insert string)
      (let ((emacs-wiki-publishing-header "")
            (emacs-wiki-publishing-footer ""))
        (emacs-wiki-replace-markup))
      (buffer-string))))

../emacs/emacs-wiki-config.el