Bouton d'ouverture d'un classeur choisi

Sub ouvrirTXT()
Application.ScreenUpdating = False
Dim stFichier$
stFichier = Application.GetOpenFilename(" Fichier Texte (*.txt), *.txt")
If stFichier = False Then Exit Sub
With Application.FileSearch
   .NewSearch
   .LookIn = Left(stFichier, InStrRev(stFichier, "\"))
   .Filename = "*.txt"
   .Execute
For Each f In .FoundFiles
Workbooks.Open Filename:=f
ActiveWorkbook.Close False
Next f
End With
Application.ScreenUpdating = True
End Sub

Option Explicit
Dim f As String
Private Sub CommandButton1_Click()
f = Application.GetOpenFilename
CommandButton2.Caption = f
End Sub
Private Sub CommandButton2_Click()
If f <> "" Then Workbooks.Open f
End Sub

Option Explicit
Dim f As Variant
Private Sub CommandButton1_Click()
f = Application.GetOpenFilename(, , , , False)
CommandButton2.Caption = f
End Sub
Private Sub CommandButton2_Click()
If f <> "" And f <> False Then Workbooks.Open f
End Sub