Salut BenBeer,
Salut l'équipe,
en formules, moi pas capable, mais en VBA...
Résultat en cliquant sur [F1].
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
'
Dim iRow1%, iRow2%
'
If Not Intersect(Target, [F1]) Is Nothing Then _
Range("A2:A" & Range("A" & Rows.Count).End(xlUp).Row).Sort key1:=[A2], order1:=xlAscending, Orientation:=xlByRows, Header:=xlNo: _
Target.Validation.Delete: _
iRow1 = Columns("A").Find(what:=[E1], lookat:=xlPart, LookIn:=xlValues, searchdirection:=xlNext).Row: _
iRow2 = Columns("A").Find(what:=[E1], lookat:=xlPart, LookIn:=xlValues, searchdirection:=xlPrevious).Row: _
Target.Validation.Add Type:=xlValidateList, Formula1:="=A" & iRow1 & ":A" & iRow2 & ""
'
End Sub
A+