I need

again ...
I am sloooowly working my way through my ebooks, converting all those texts I collected during the past 10 years ...
I use calibre to convert to htmlz, then take the html, import into word, format to my heart's content and make my ebooks ... works for me
Now I have many texts that use a "blank line" as an indicator for a scene break - if I convert those, the line disappears - I to manually insert it again ...
Is there a way to tell calibre "put something like »scene break here« into every blank line you find in the text I gave you to convert"?