To write a module plug-in for RSSFit, you can refer to the RSSFit plug-in sample available in our download area.
You can follow the instructions commented in the plug-in sample and modify the code to match you needs. This job usually takes no more than 15 minutes if you are handy with your targeted module.
Although coding a plug-in for RSSFit is not so difficult, we do not encourage you to do it without a basic understanding of programming in PHP.