htaccess Elite

I have a site that uses legacy ugly urls like so:

http://mysite.com/blogger.php?blogger=9624

So, in my quest for pretty urls, I have used mod_rewrite and apache to change the above to this:

http://mysite.com/blogger/9624/

Here is my rewrite rule:

RewriteRule ^blogger/([0-9]+)/$ /blogger.php?blogger=$1

The above works fine. Now,the problem is my ugly urls are linked to from external websites. So I need to 301 redirect "http://mysite.com/blogger.php?blogger=9624" to "http://mysite.com/blogger/9624/". How do I do that with my rewrite rule without having an endless loop?