Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objnet = CreateObject("wscript.network")
Set olkApp = CreateObject("Outlook.Application")
Set objFolder = objFSO.GetFolder("K:\")
For Each objFile In objFolder.Files
   If LCase(objFSO.GetExtensionName(objFile.Name)) = "pst" Then
     olkApp.Session.AddStore objFile.Path
   End If
Next