User Control with PlaceHolder and some pre-defined elements

Enviroment: Asp.Net 3.5, VS 2008, Windows XP

Hello, i have a user control (uc:StackUC) such as:

<fieldset>
<legend>blablabla</legend>
<%-- other fields --%>
<asp:PlaceHolder ID="contentHolder" runat="server"></asp:PlaceHolder>
<asp:Button runat="server"/>
</fieldset>

My idea is to use on my pages, like this (due to lots of repetition):

...
<uc:StackUC>
<label>specific content</label>
<%-- blablabla --%>
</uc:StackUC>
...

I believe it has to do with templated user controls, however, all the examples i find have no pre-defined user controls, and are aimed at doing

<%#Container.Index %> (or any other property)

Which is not useful to me.

Thanks in advance.

References for templated user controls: http://leedale.wordpress.com/2007/08/开发者_开发百科11/creating-a-templated-user-control-with-aspnet-20/, http://msdn.microsoft.com/en-us/library/36574bf6(vs.71).aspx#Y456

The following codes are simplified.

The user-control ascx:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="BaseFormControl.ascx.cs"
    Inherits="SOPR.CustomForms.BaseFormControl" %>
<fieldset class="fset1">
</fieldset>

This is my user control code-behind:

public partial class BaseFormControl : System.Web.UI.UserControl
    {



        [TemplateContainer(typeof(ContentContainer))]
        [PersistenceMode(PersistenceMode.InnerProperty)]
        [TemplateInstance(TemplateInstance.Single)] //IMPORTANT, makes controls visible in page code-behind

        public ITemplate Content { get; set; }



   void Page_Init()
        {




            if (Content != null)
            {
                ContentContainer cc = new ContentContainer();
                Content.InstantiateIn(cc);
                contentHolder.Controls.Add(cc);
            }
        }

My usage in the view:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="AddOperator.aspx.cs"
    Inherits="SOPR.Cadastro.AddOperator" MasterPageFile="~/MasterPage.Master" %>

<asp:Content ContentPlaceHolderID="ContentPlaceHolder1" ID="maincont" runat="server"     EnableViewState="true">
    <uc:BaseFormControl ID="BaseFormControl1" runat="server">
        <Content>
      <asp:TextBox runat="server" CssClass="keytbcss" MaxLength="4" ID="keytb"
                NewLine="false" />
        </Content>
    </uc:BaseFormControl>

This is actually a copy of the results of my other question post.