A VBA procedure to be called by a "run a script" rule action needs a MailItem or MeetingItem as its parameter. That item is processed by the code:
Sub RunAScriptRuleRoutine(MyMail As MailItem)
Dim strID As String
Dim olNS As Outlook.NameSpace
Dim msg As Outlook.MailItem
Dim rply as Outlook.MailItem
strID = MyMail.EntryID
Set olNS = Application.GetNamespace("MAPI")
Set msg = olNS.GetItemFromID(strID)
' do stuff with msg, e.g.
Set rply = msg.Reply
rply.Body = "What you want the reply to say."
rply.To = "(e-mail address removed); (e-mail address removed)"
rply.Send
Set msg = Nothing
Set rply = Nothing
Set olNS = Nothing
End Sub
For more examples of "run a script" rule actions, see:
http://www.outlookcode.com/d/code/zaphtml.htm#ol2002
http://www.outlookcode.com/codedetail.aspx?id=1494