If your podcast is hosted on Wordpress and you are using the plugin PowerPress Plugin (https://wordpress.org/plugins/powerpress/) to generate your podcast feed RSS you are able to redirect your podcast feed to RSS.com you have to follow these steps:
1. Install the plugin "Redirection" (https://wordpress.org/plugins/redirection/)
2. Activate the plugin
3. Access the redirect plugin clicking by "Tools" > "Redirection"
4. Add a new Redirect clicking by the "Add new" button
5. Your feed setup is usually https://yourcustomdomain/feed/podcasts/ so your setup will be:
Source URL: /feed/podcast/
Query parameters: exact match in any order
Target URL: your new RSS.com RSS feed URL
6. Click "Add redirect" button
7. If you activated have any kind of cache inside your Wordpress installation you have to clear your Wordpress cache.