in VB6 è possibile.

in un form metti 2 pulsanti, e copia queste righe nel codice del Form:

codice:
Private Declare Function mciSendString Lib "winmm.dll" Alias _
        "mciSendStringA" (ByVal lpstrCommand As String, ByVal _
        lpstrReturnString As String, ByVal uReturnLength As Long, _
        ByVal hwndCallback As Long) As Long

Private Sub Command1_Click()
'Apre il CD
Dim retvalue As Long
retvalue = mciSendString("set CDAudio door open", _
returnstring, 127, 0)
End Sub

Private Sub Command2_Click()
'Chiude il CD
Dim retvalue As Long
retvalue = mciSendString("set CDAudio door closed", _
returnstring, 127, 0)
End Sub
Boolean