good stuff, will install that, see how it goes,
fwiw, the regex expression worked beautifully for what i actually wanted, converting destination footnote links into dual direction ones
first gave footnotes ids like id="f-1", id="f-20" etc
then converted destination placeholders like
<a id="filepos789849"></a>20.
using regex search expression
"></a>(.*?)
and replace expression
" href="Chapter-01.html#f-\1">\1</a>
resulting in
<a id="filepos789849" href="Chapter-01.html#f-20.">20.</a>
only needed to hit "replace and find" till the end of each chapter, change chapter numbers and continue, very quick,
then just used normal mode to find ."> and replace with "> (to correct the ids)