my code below works. this method requires full-name:
Assembly.GetType(string FullName)
Assembly assembly = Assembly.Load("App_Web_mywsc.ascx.cdcab7d2");
foreach (Type oType in assembly.GetTypes())
{
System.Diagnostics.Debug.WriteLine(oType.FullName);
}
Type controlType = assembly.GetType("ASP.mywsc_ascx");
object controlss = Activator.CreateInstance(controlType);
myDIV.Controls.Add((Control)controlss);