Many Microsoft application file formats use OLE Structured Storage for their data. They store the Document Summary Properties as one of the streams in the Structured Storage. Microsoft provides an ActiveX control called DSOleFile (hosted in DSOFile.dll) that enables you to access and modify these properties outside the application. The ActiveX control can be downloaded from here. Download and install the ActiveX control.

The following code snippet uses the ActiveX control to extract the Application Name that created the document.

'
' Get DSOFile.dll from
' http://support.microsoft.com/default.aspx?scid=kb;EN-US;q224351
'

Function GetFileCreator(ByVal FileName As String) As String
    Dim DSO As Object
    Dim DPs As Object

    Set DSO = CreateObject("DSOleFile.PropertyReader")
    Set DPs = DSO.GetDocumentProperties(FileName)
    GetFileCreator = DPs.AppName
    Set DPs = Nothing
    Set DSO = Nothing
End Function