ExtJs HtmlEditor image upload?

I am using ExtJs4.2.1 as the frontend and asp.net mvc 4 as the backend. My customer has the following requirements:

They wanna copy bunch of stuff from a document(like .docx file etc.) directly into the extjs's htmleditor. So, there will inevitably be mixtures of rich texts and images inside the editor, which is a problem because the html editor of extjs can not upload picture directly. So, I wonder if there is an solution for this? I googled a lot, and some of the answers will involve to add a extra button for the editor and pop up an add File panel to let the customer insert image. I think it is little bit tricky. Could I filter out the picture in the editor and directly upload it without popping up another selection panel? Anyway, is there a more elegant way to do things like this?

Any help relating this topic will be really appreciated.