codice:
Function OpenCD(CD_Drive As String) As Boolean
Dim ReturnString As String * 30
CloseCD
CD_Drive = Mid$(CD_Drive, 1, 1) + ":\"
OpenCD = Not CBool(mciSendString("open " + CD_Drive + " Type cdaudio alias cdr wait shareable", ReturnString, Len(ReturnString), 0))
If OpenCD Then mciOpen = True Else mciOpen = False
mciSendString "set cdr time format tmsf wait", vbNullString, 0, 0
End Function
Guarda se così funziona, devi passare a questa funzione una stringa contenente la lettera del driver (e.s. "D:\")

Fammi sapere, ciao