ASP.NET how to create container control which will have exactly two containers?

How to create a web control which will contain exactly two containers in ASP.NET 3.5. Like always exactly two columns (divs). I know default way allows you to have ControlCollection by overriding CreateControlCollection() method, but whis allows you to have only one container (or variable number of containers). Is there a way to always have exactly two containers in web control?

I want to archive开发者_开发知识库 something like this:

<MyControl> 
<LeftContainer> ... </LeftContainer>
<RightContainer> ... </RightContainer>
</MyControl>

There is no way to do it in ASP.NET 3.5