OK, so here is the answer.
With ASP.Net 2.0 it is actually very simple:
<system.web>
<urlMappings>
<add url="~/Default.aspx" mappedUrl="~/MyStartPage.aspx"/>
</urlMappings>
</system.web>
In ASP.Net 1.1 Application_BeginRequest event needs to be handled in the
Global.asax
Sub Application_BeginRequest(ByVal sender As Object, ByVal e As EventArgs)
If Request.RawUrl.ToUpper().IndexOf("DEFAULT.ASPX") > -1 Then
Response.Redirect("MyStartPage.aspx")
End If
End Sub
Of course, "MyStartPage.aspx" can be stored as a configurable setting in
web.config.
TJ