Why don't you use a class data member in the code-behind, set the value of that data member and use if in your HTML instead of setting the label's text property.
In the code-behind:
public class myclass
{
public string mylabel = "";
}
In the HTML:
<ContentTemplate>
You are in
<asp:Label ID="lblPos" runat="server"><%=mylabel%></asp:Label><sup>th</sup> Position
</ContentTemplate>