how do I fina a contact with and exchange alias

Function userDetail(theAlias As String) As String

Dim olkDL As Outlook.DistListItem
Dim olkEntry As Outlook.Recipient
Dim olkContact As Outlook.ContactItem
Dim intCount As Integer
Dim strAddress As String
Dim strName As String
Dim oApp As Outlook.Application
Dim oNS As Outlook.Namespace
Dim oALs As Outlook.AddressLists
Dim oGal As Outlook.AddressList
Dim oEntries As Outlook.AddressEntries
Dim oEntry As Outlook.AddressEntry
Dim oAlias As Outlook.ContactItem

On Error GoTo outlookClosed

Set oApp = Outlook.Application
On Error GoTo 0

Set oNS = oApp.Session ' Get the MAPI namespace.
Set oALs = oNS.AddressLists ' Get the Global Address List.
Set oGal = oALs.Item("Global Address List") ' Get all the entries.

Alias = LCase(Trim(theAlias))

Set oEntries = oGal.AddressEntries
Set oEntry = oEntries(Alias)

'********************************************
'OUTPUT
'********************************************

'userDetail = oEntry.GetExchangeUser.JobTitle
'userDetail = oEntry.GetExchangeUser.Alias
'userDetail = oEntry.GetExchangeUser.Department
'userDetail = oEntry.GetExchangeUser.OfficeLocation
'userDetail = oEntry.GetExchangeUser.StreetAddress
'userDetail = oEntry.GetExchangeUser.Address
'userDetail = oEntry.GetExchangeUser.City
'userDetail = oEntry.GetExchangeUser.StateOrProvince
'userDetail = oEntry.GetExchangeUser.MobileTelephoneNumber

'userDetail = oEntry.GetExchangeUser.MobileTelephoneNumber
userDetail = oEntry.GetExchangeUser.OfficeLocation

'********************************************
'OUTPUT
'********************************************

Exit Function

outlookClosed:
userDetail = False

Exit Function

End Function