My Web Parts in ASPX Page Temlate

My task: create page template with contain web parts developed by me.

Here what I've done: I've developed my own web part as it was described in Kentico Developer Guide. This is very simple one so I can write it's code.

ascx file:

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="customWebPart.ascx.cs" Inherits="CMSWebParts_Custom_customWebPart" %>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>

cs file:

using CMS.PortalControls;

public partial class CMSWebParts_Custom_customWebPart : CMSAbstractWebPart
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Label1.Text = (string)this.GetValue("Text");
    }
}

As you can see this web part is only a label and you can edit it's text via web part properties.

After create I've of course registred this web part and add a property "Text".

Next step is quite problematic. I need to create a page template. It's possible to write something like that:

<cms:CMSPagePlaceholder ID="Holder" runat="server">
        <LayoutTemplate> 
            <cms:CMSWebPartZone runat="server" ID="zone" WebParts="custom"/>           
        </LayoutTemplate>
    </cms:CMSPagePlaceholder>

and add my web part via cms desk but it's not the point. I need to put this web part exactly into page template, and it should by editable from cms desk.