That is exactly what I want!! Thank you!
Added bonus: it seems I can use this with any other mode.

I've updated the code:
https://github.com/sri/dotfiles/commit/3b2e42f488393dfc0f7fa91887877af5b195a20c

And I'm invoking it like so:

(add-hook 'org-mode-hook
          (lambda ()
            (my-org-create-dynamic-link
             "\\([[:alpha:]]\\{2,5\\}-[[:digit:]]+\\)"
             "https://www.some-ticket-system/%s")))

-Sriram


On Sun, Jul 10, 2016 at 2:19 PM, John Kitchin <jkitchin@andrew.cmu.edu>
wrote:

> It kind of sounds like you want the button-lock package. See
>
> http://kitchingroup.cheme.cmu.edu/blog/2015/03/18/Clickable-links-for-Twitter-handles-in-Emacs/
> for example (and search "clickable text" on my blog for other examples).
>
> Maybe something like:
>
> #+BEGIN_SRC emacs-lisp
> (require 'button-lock)
> (global-button-lock-mode)
>
> (defvar ticket-regexp "\\([[:alpha:]]\\{2,5\\}-[[:digit:]]+\\)")
>
> (button-lock-set-button
>  ticket-regexp
>  (lambda ()
>    (interactive)
>    (save-excursion
>      (goto-char (previous-single-property-change (point) 'button-lock))
>      (looking-at ticket-regexp)
>      (browse-url (format "http://www.some-ticket-system/%s" (match-string
> 0)))))
>  :face 'org-link)
> #+END_SRC
>
> You get no export with this, but it has the functionality you want I
> think.
>
> Sriram Thaiyar writes:
>
> > Hi-
> >
> > I've implemented "dynamic links" which are like plain links but for
> > arbitrary regular expressions.
> >
> > I was wondering if there was a better way to do this?
> >
> > You can see the implementation here:
> >
> https://github.com/sri/dotfiles/commit/cd3429ce0c8e637c803835299c2ed4653d19a5fb
> >
> > (This works with Org-mode version: 8.3.4 - 8.3.4-88-g792bb9-elpa.)
> >
> > With this config:
> >
> >     (add-to-list 'my-org-dynamic-links-matcher
> >                  '("\\([[:alpha:]]\\{2,5\\}-[[:digit:]]+\\)"
> >                    "https://some-ticketing-system.org/%s"))
> >
> > a string like `TEST-122' is turned into a link, as you type it in.
> > And when you click on that link, it'll visit this URL:
> > https://some-ticketing-system.org/TEST-122
> >
> > There are some things that gave me problems:
> >
> > - I can't hit <return> and have it follow the link. For this, it seems
> >   like I would need to advice the `org-return' function.
> >
> > - Despite the fact that the `TEST-123' has a `htmlize-link' text
> property,
> >   it errors out with "No link found". To fix that, I needed to add a
> hook to
> >   `org-open-at-point-functions'.
> >
> > - I had to copy a bunch of code from `org-activate-plain-links' to get
> >   this to work.
> >
> > Thanks,
> > -Sriram
>
>
> --
> 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
>