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
Group: redirections
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.