Is it a way to remove or hide http referer information in request header?

I have the following code to open an url, but it does only if the user input the full url with "http://"

dim objXMLHTTP

URL = Request.form("URL")
if ( URL = "" ) then
'URL = ""
URL = Request.QueryString("url")
end if

Set objXMLHTTP = Server.CreateObject("Microsoft.XMLHTTP")
objXMLHTTP.Open "GET", URL, false
strPlainText = StripHtml(RemoveHtml(objXMLHTTP.responseText))

Thank you in advance