Need to determine sender email address in Outlook 2007

[Edge003]

I have a macro in Excel 2007 that I'm designing to send a user a confirmation email once an appointment has been made. The macro opens an Outlook 2007 new message window with the date & time of the appointment. What I'm trying to do is detect the user's (sender's) email address (should be the "from:" by default) once the new message window is opened and CC the user in the confirmation email. I have read about the AddressEntry.GetExchangeUser method, but not sure how to use it. The user will be part of a GAL. Here is my code:

Sub Saveas()
Dim WshShell As Object
Dim OutApp As Object
Dim OutMail As Object

Set WshShell = CreateObject("WScript.Shell")
Set OutApp = CreateObject("Outlook.Application")
OutApp.Session.Logon
Set OutMail = OutApp.CreateItem(0)

Dim strbody As String
strbody = "Hello," & vbNewLine & vbNewLine & _
"This is to confirm that you have an appointment with Finance on " & _
Workbooks("FinanceAppointments.xlsm").ActiveSheet.Range("G3") & " " & _
Workbooks("FinanceAppointments.xlsm").ActiveSheet.Range("H3") & vbNewLine & _
"between " & Workbooks("FinanceAppointments.xlsm").ActiveSheet.Range("C8") & "hours." & _
" Please make a note of your appointment timeslot." & vbNewLine & "Thank you." & _
vbNewLine & vbNewLine & _
"The Finance Office"

With OutMail
.To = "name@email"
.CC = ""
.BCC = ""
.Subject = "Finance Appointment Confirmation"
.Body = strbody
.Display
End With

WshShell.SendKeys ("%s")

On Error GoTo 0

Set OutMail = Nothing
Set OutApp = Nothing

MsgBox "Your appointment request has been saved. Finance Appointments will now close.", vbInformation, "Appointment Confirmation"
Sheets("EnableMacros").Select
Sheets("EnableMacros").Range("F2").Select
ActiveWorkbook.Close True
Application.Quit
End Sub

Any help would be appreciated!