Sub Masquer()
ActiveSheet.Range("$C$4:$C$50000").AutoFilter
ActiveSheet.Range("$C$5:$C$50000").AutoFilter Field:=1, Criteria1:="=" & [A1], Operator:=xlAnd
End Sub
Sub Démasquer()
ActiveSheet.Range("$C$5:$C$50000").AutoFilter Field:=1
Selection.AutoFilter
End Sub