Boîte de dialogue

Sub OuvreFichier()
    ChDrive "C:\"
    ChDir "C:\Arsiv\"
    LeFichierChoisi = Application.GetOpenFilename("Fichiers MP3 (*.mp3), *.mp3")
    If VarType(LeFichierChoisi) = vbBoolean Then
        Exit Sub
    Else
        Workbooks.Open Filename:=LeFichierChoisi
    End If
End Sub

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