External with parameter

[Chris Pienta]

Anyone know how to add an external alias to a js file with a parameter.  Like this:
http://www.externalapi.com/toolkit.js?key=Gmjtd%7Cluub2l01n9%2Crx

If I try it like this:
            bundles.AddUrlWithAlias("extapi",     "http://www.externalapi.com/toolkit.js?key=Gmjtd%7Cluub2l");

I get the errors:
Cannot determine the type of bundle to add. Specify the type using the generic overload of this method..