This really is a neat script, I was on the lookout for something just like this.

A solution for the above problem with translation. If you’re like me and using WordPress language files to translate the site change this line:
$link = str_replace($reply_link_text, ‘Reply to ‘ . $author, $link);
$link = str_replace($reply_link_text, __( ‘Reply’, ‘nameofyourtheme’ ).’ ‘. $author, $link);

the nameofyourtheme string has to match the textdomain in your language file, in my case Im using the twentytwelve theme so I’ll just type:
$link = str_replace($reply_link_text, __( ‘Reply’, ‘twentytwelve’ ).’ ‘. $author, $link);

Please note that the .’ ‘. is added to get a space between the your “Reply” string and $author variable.