Updating empty.po files

DB Strings Translation

I am modifying and adding some file in frontaccounting (not creating new extension, but modify) and add some string that will need translation. I'm using poEdit file version 1.6.3. How can I add new string from my modified and new file to the existing po? I use Indonesian language. I hear that the application can generate .pot automatically from php. But, I don't know how to do this in poEdit because the tutorial is for the older version.