Check out the RenderControl method. It will essentially let you dump the contents of any ASP.NET page as HTML. So you can build your site dynamically, then dump it all out to HTML and upload it to your antique server.
Here's a bit of helper code that I swiped from one of my projects to get the contents of any page into a string:
public class RenderHelper
{
public static string RenderControl(Control control)
{
StringBuilder result = new StringBuilder(1024);
control.RenderControl(new HtmlTextWriter(new StringWriter(result)));
return result.ToString();
}
public static string RenderControl(TemplateControl control)
{
StringBuilder result = new StringBuilder(1024);
control.RenderControl(new HtmlTextWriter(new StringWriter(result)));
return result.ToString();
}
public static string RenderPage(string pageLocation)
{
HttpContext context = HttpContext.Current;
StringBuilder result = new StringBuilder(1024);
context.Server.Execute(pageLocation, new HtmlTextWriter(new StringWriter(result)));
return result.ToString();
}
}