While further evaluating my code, I realized that it wasn't working when target headlines contained tags. I've updated the code to handle this case -- the result is posted as a gist since it may change later on, and all of you esteemed elisp hackers can more easily contribute to it that way, until it's worthy to be considered for inclusion in contrib.
Here's the gist URL: https://gist.github.com/edgimar/072d99d8650abe81a9fe7c8687c0c993
