Private Declare Function FindWindow Lib "user32" Alias _
      "FindWindowA" (ByVal lpClassName As String, ByVal _
      lpWindowName As String) As Long
 
 
 
Sub WindowsAPI()
 
    Dim hWndForm  As Long
 
    If Val(Application.Version) >= 9 Then
        hWndForm = FindWindow("ThunderDFrame", Me.Caption)
    Else
        hWndForm = FindWindow("ThunderXFrame", Me.Caption)
    End If
 
    Debug.Print hWndForm
End Sub