Thanks for the feedback. Yes, I run a web server. The issue is really that I need a command line tool to download newspapers once each day. Once I did that, I could create a script to sync the directory my newspaper downloader downloads into with Calibre on my desktop machine and Calibre could then handle the conversion process for my Kindle.
The key here is that I really like how Calibre downloads the newspapers. If that is done with a script itself, all I would need is that and I could use cron to schedule it to run each day.