lo he conseguido de otra forma
Código PHP:
Set Upload = Server.CreateObject("Persits.Upload.1")
Upload.ProgressID = Request.QueryString("PID")
'Count= Upload.Save(Server.MapPath(carpeta_pujar))
Upload.Save
For Each File in Upload.Files
NEW_NAME = replace(File.FileName," ", "_")
File.SaveAs Server.MapPath(carpeta_pujar & NEW_NAME)
'Response.Write "New name: " & File.FileName & "<BR>"
next
%>
pero ahora no se como hacer para filtrar que solo puedan subir ficherxos .pdf