Redirect just about everything except…

Hey John, good plugin.

I’m trying to do something that might be difficult, but perhaps you can help:

I’m looking to redirect a podcast feed URL, which I know is easy to do with a 301 redirect, and that’s done, but I want the rest of the site (EXCEPT wp-admin) to also redirect to the destination of the URL.

So I still want wp-admin to work, but the podcast feed has a dedicated destination, and everything else will just get redirected to the homepage of my site.

How do I best accomplish this? Thanks!