How to generate .POT?

Hello All,

I'v followed the process of *Adding new language* (
https://wiki.documentfoundation.org/LibreOffice_Localization_Guide/Adding_a_New_Language_or_Locale)
to add one new language and it worked.

It:s the time to localise the "new language string".

Is there any guide online i can follow to regenerate the PO file?
I known there is some l10ntools to extract string from src to POT, but i
fail to figure out how to get it work.

I am now working on the approach of adding new entry manually and want to
know the more automatically way to do so.

PS. I am on windows platform.

Thanks!

-- 
yours sincerely,
                     Jeff