IMDb Advanced Search question

The Internet Movie Database has a page where you can do a search for movies using a whole bunch of different criteria at the same time, from part of the title to cast members to genre to runtime. However, one criterion that is missing is searching by a name of the character in the cast. So if, for example, you want a list of movies to feature both Donald Duck and Mickey Mouse, you seem to be out of luck. Is there a way to add character search to IMDb's advanced searching?

If you look at the URLs returned when you do a search, you'll get something like this:

http://www.imdb.com/search/title?release_date=1930,1940&title=movie

You can probably guess that this searches for movies that have the word "movie" in the title, and which were released between 1930 and 1940 (including 1940). I tried setting up a search such as the following:

http://www.imdb.com/search/title?release_date=1930,1940&character=raleigh

This in theory ought to be something that would search for 1930s movies that have a character named Raleigh; I was thinking something along the lines of Vincent Price's portrayal of Sir Walter Raleigh in The Private Lives of Elizabeth and Essex. Instead, that URL produces a list of 27470 titles.

You can seach from the drop-down box near the top of any IMDb page for one criterion; a search for "Elizabeth and Essex" will give the following URL:

http://www.imdb.com/find?s=tt&q=elizabeth+and+essex

(If you search for something that only yields one result, you will probably get redirected to that one movie, although there might be an option not to do automatic redirection.)

Similarly, you can search for a character:

http://www.imdb.com/find?s=ch&q=raleigh

But there doesn't seem to be a way to combine these search terms with the ones in the advanced search.

Does anybody have any good ideas?