There isn't one. So your choices are to write a script yourself, or to beg someone else to do it. The first isn't very practical unless you have some programming skills, and the second you've just done.
In the meantime, you can use this Web search...
http://www.metacritic.com/search/process?sort=relevance&termType=all&ty=1&x=33&y=10&ts=%s%u
Add the URL at Preferences - Web search.