I found the solution myself:

Now the scrips works just fine.

Public Sub saveAttachtoDisk(itm As Outlook.MailItem)
Dim objAtt As Outlook.Attachment
Dim saveFolder As String
saveFolder = "H:\minox\Data\A0021115\Docs"
     For Each objAtt In itm.Attachments
          If InStr(objAtt.DisplayName, ".pdf") Then
          objAtt.SaveAsFile saveFolder & "\" & objAtt.DisplayName
          Shell """C:\Program Files\Adobe\Reader 11.0\Reader\acrord32.exe"" /h /p """ + saveFolder & "\" & objAtt.DisplayName + """", vbHide
        End If
Set objAtt = Nothing
Next
End Sub