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)
Const SW_SHOWNORMAL = 1
Sub aa()
Dim Ret As Variant
ChDir ("C:\Arsiv") 'à adapter
Ret = Application.GetOpenFilename("Fichiers MP3 (*.mp3), *.mp3")
If Ret = False Then Exit Sub
MsgBox Ret 'pour visualiser (à jeter)
'--- Lance le MP3 ---
ShellExecute Application.hwnd, "open", Ret, vbNullString, vbNullString, SW_SHOWNORMAL
End Sub