I manage to create UserControls (.ascx pages) and i call them at the html coding, but I did not manage to display those UserControls from my vb sub

This is how I crate the UserContorls:
<%@ register tagprefix="aspx4devs" tagname="myheader" src="header.ascx" %>

this is how I Call it
<aspx4devs:myheader id="Myheader1" runat="server" NAME="Myheader1"></aspx4devs:myheader>

But I nead to Call it From a sub becaouse I use Code behind and ASP.NET with Visual Basic.NET