Sorry but you cannot put server controls or server side code in the html wysiwyg editor and you can't use included CMS content features inside other CMS content features. You would have to build a custom feature that has your control in the middle and editable html above and/or below it. You could easily make the html parts as simple module settings sort of like what we have for the upper and lower side bar content in the blog, so it would be pretty easy to build a feature like that if you are a developer.
Hope that helps,
Joe