Saving attachments from an Exchange Public Folder

[bxgti4x4]

We have recently upgraded from Mailgate to Microsoft Exchange. In Outlook on my PC I had the following code to saved a particular attachment to a specified folder:

Dim myOlApp As Outlook.Application
    Dim myInspector As Outlook.Inspector
    Dim myItem As Outlook.MailItem
    Dim myAttachments As Outlook.Attachments
    Set myOlApp = CreateObject("Outlook.Application")
    Set myInspector = myOlApp.ActiveInspector
    If Not TypeName(myInspector) = "Nothing" Then
        If TypeName(myInspector.CurrentItem) = "MailItem" Then
            Set myItem = myInspector.CurrentItem
            Set myAttachments = myItem.Attachments
            'Prompt the user for confirmation
            Rem Dim strPrompt As String
            Rem strPrompt = "Are you sure you want to save the first attachment in the current item to the C:\ folder? If a file with the same name already exists in the destination folder, it will be overwritten with this copy of the file."
            Rem If MsgBox(strPrompt, vbYesNo + vbQuestion) = vbYes Then
                myAttachments.Item(1).SaveAsFile "N:\DOCS2\Positions\" & _
                myAttachments.Item(1).DisplayName
            Rem End If
        Else
            MsgBox "The item is of the wrong type."
        End If

The message which contains the attachment I wish to save now appears in an Exchange Public Folder and, when I run the code, the message box appears telling me that the item is of the wrong type.

I think the problem lies in the phrase "Dim myItem As Outlook.MailItem" but I cannot find any information which refers to Exchange. I would be grateful if someone could set me right.

John