ASP。NET:可能创建包含内部标记内容的用户控件?

I'm trying to achieve something google isn't able to give answer. I'm trying to create an asp.net usercontrol that when I put content into it's open close tag will include it for me to be still able to acess it's content by ID from the Parent. Here is an exemple of what I want to achieve.I'm trying to achieve something google isn't ab