You would have to call the function properly, but I think this line might kill the functionality on quite a few hosters :
Set oShell = Server.CreateObject("Wscript.Shell")
Once you have inserted the code somewhere (maybe just the admin_accounts_pending.asp page) then you can do something like this :
Response.Write NSlookup(ip goes here)
The problem is, how do you tell the bad apple from all the good apples on the same ISP ?<