custom html code in a repeater

Question

I'd have a repeater with some group logic inside. Basically, on the ItemDataBound method, I show or hide some controls inside the item.

But I've a problem, I want to add a header group template (and footer) : < ul> and < /ul>

For example, the following code :

<ul id="UlControl" runat="server"><asp:Label id (....) </ul> 

and then (in the databound method)

UlControl.Visible = false; 

Result : All the html code inside < ul> / < /ul> will be hidden.

I tryied to put a and inside an html < ul> but asp .net will auto close the < ul>.

I think about a placeholder but is it possible to add some code without validation ?

Regards