Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Const WM_COMMAND = &H111

Private Sub Command1_Click()
    Dim hWnd As Long
    hWnd = FindWindow("#32770", "")
    SendMessage hWnd, WM_COMMAND, "12479", 0
End Sub

Private Sub Command2_Click()
    Dim hWnd As Long
    hWnd = FindWindow("#32770", "")
    SendMessage hWnd, WM_COMMAND, "12514", 0
End Sub