Call ShellExecute(hwnd, "Open", "C:\test\file.xls", "", App.Path, 1)

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" ( _
  ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, _
  ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As _
  Long) As Long