RewriteRule for RSS redirect?

I used to hand-code an RSS feed. Now I have WordPress, yay!

I got rid of my old feed, but now I see a lot of search errors from users/spiders not finding the old feed.

I’ve tried this RewriteRule in .htaccess, but it doesn’t seem to be working. ck.xml still gets a file-not-found error.

RewriteRule ^ck.xml$ /blog/?feed=rss2 [R=301,L]

If I try RedirectMatch, the ? gets converted into URL encoding and fails:

RedirectMatch permanent ^/CK/ck.xml$
http://www.coreknowledge.org/blog/?feed=rss2

error page shows /blog/%3ffeed=rss2

(could that just be a character encoding issue on that shtml page?)

what’s funny is that the website error log does show the correct path to the feed as a “file not found” when using the RedirectMatch method.

Ideas?