Define language in code

I'm trying to create a language definition without using a separate XML file. I started with an instance of "SyntaxLanguage", but apparently you have to do something with it before it can be used. The following code compiles OK, but when I set the syntaxEditor.Document.Text property, I get an "Object does not exist" error from the DLL:

SyntaxLanguage newLanguage = new SyntaxLanguage("MediaScript", false);
syntaxEditor.Language = newLanguage;

Is there a code sample that shows what is needed to do this correctly?

Regards,
Scott