Une autre manière est de choisir le dossier avec Application.FileDialog :
Sub Recherche()
Dim cible$, fso As Object, ncol%, dossier As FileDialog, sf$, lig&, f As Object, wb As Workbook, plage As Range, i&, j%
cible = "*" & [F1].Text & "*"
Set fso = CreateObject("Scripting.FileSystemObject")...