title_body: How to call a plugin from command line? How to, lets say, hyphen an ebook with Hyphenate This! plugin from command line?
upvoted_answer: How to work with the Calibre command line can be found in this manual.
  
  Use this command to show what you can do with plugins:
  
  calibre-customize -h
  
  
  I'm afraid Hyphenate This! is just a GUI plugin without a command line interface.
  
  (For more advanced work with plugins, look at API documentation.)