Con qualche piccola modifica mi funziona...
codice:
<%@ language = vbscript %> 
<% option explicit %> 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> 
<title>Nuova pagina 1</title> 
</head> 

<body> 
<% 
call SaveFile("/scrivimi.html",geturl("http://www.miosito.it/test.asp")) 

Function GetUrl(Url) 
	Dim Http 
	Set Http = Server.CreateObject("Microsoft.XMLHTTP") 
	Http.open "GET",Url,False 
	Http.Send() 
	GetUrl = Http.ResponseText 
	Set Http=Nothing 
End Function 

Function SaveFile(PathFile,Content) 
	Dim Fso, File
	Set Fso = Server.CreateObject("Scripting.FileSystemObject") 
	Set File = Fso.OpenTextFile(Server.MapPath(PathFile),2,true) 
	File.Write Content 
	File.Close() 
	Set File = Nothing 
	Set Fso = nothing 
End Function 
%>
</BODY>
</HTML>
grazie