How Do I Fix This? Some subscribers have a weird URL.

Here the problem. I moved from a different system to WordPress. When I did this I did a 301 redirect to the wordpress feed. I also have the feedburner plugin so that URL got forwarded to feedburner.

In the end, serveral subscribers now have a feed URL of https://mysite.com/feed/?category_name=index.xml and I want be able to eliminate the feedburner feed. The only thing holding this feed together is the fact that the feedburner plugin is still installed and working. I have tried something like Redirect 301 /feed/?category_name=index.xml https://mysite.com/feed/, but apparently that doesn’t work for parameters. Any ideas? I would be willing to go so far as hacking code to get it fixed.