How to mixin multiple editors like HTML/CSS/JS

Hi,

I would like to create an XML-based editor that for some elements or attribute has embedded editor of other language (similar like HTML editor mix with C#, JavaScript or CSS). I know that I should use IProjectionBuffer and IBufferGraph but there is no documentation or sample how to do that. I found some question when there was promised release of sample how to do that but I cant find it: http://go4answers.webhost4life.com/Example/create-editor-language-mixins-4985.aspx.

Does any body know how to do that?