Regex Redirection

I’ve noticed a pattern in many of our 404’s. They come in the flavor of:

http://www.domain.com/dir/sub/.html

And the correct page needs to be

http://www.domain.com/dir/sub

Is it possible to use Regex to take care of this entire pattern, or do I need to do each url, one by one?

My guess at Regex would be:

\/*\/*\/\.html

\/*\/*\/

Thoughts?

http://wordpress.org/plugins/redirection/