This is a tricky problem to generally solve. I think this does it
approximately well enough. It is lightly tested and works by exactly
matching headlines at subsequent levels. It will be problematic if you have
headlines with : in them, and it assumes there is a level 1 headline to
start in.

#+BEGIN_SRC emacs-lisp
(defun xpath-follow (path)
  (let* ((fields (split-string path "::"))
(fname (car fields))
(paths (split-string (cadr fields) ":"))
(level 0)
(current-point (point))
cp hls n found)
    (org-mark-ring-push)
    (find-file fname)
    (save-restriction
      (while paths
(setq cp (pop paths))
(incf level)
(setq hls (org-element-map (org-element-parse-buffer) 'headline
    (lambda (hl)
      (when (eq level (org-element-property :level hl))
hl))))
(setq n (-find-index (lambda (hl)
       (string= cp (org-no-properties
    (org-element-property :raw-value hl))))
     hls))
(if (not n)
    (progn
      (goto-char current-point)
      (user-error "%s not found" cp))
  (goto-char (org-element-property :begin (nth n hls)))
  (org-narrow-to-subtree))))))

(org-link-set-parameters
 "xpath"
 :follow 'xpath-follow)
#+END_SRC


John

-----------------------------------
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu


On Mon, Mar 12, 2018 at 8:08 AM, ST <smntov@gmail.com> wrote:

> Hello,
>
> Ss Christian has pointed out - introduce a separate CUSTOM_ID for text
> with fixed structure and rather short verses is too heavy.
>
> I do need to write a custom link type, if this use case is not of common
> interest for the orgmode community.
>
> Thank you,
>
>
> On Mon, 2018-03-12 at 15:10 +0100, Nicolas Goaziou wrote:
> > Hello,
> >
> > ST <smntov@gmail.com> writes:
> >
> > > I'm not that experienced in writing in lisp. Is it difficult to create
> > > such custom link type? What is the closest link type that you would
> > > recommend to take as starting point (link on code, if possible)?
> >
> > I'm not answering your question, but I suggest to use a CUSTOM_ID
> > instead. This is readily available.
> >
> > Regards,
> >
>
>
>