Private Sub Worksheet_change(ByVal Target As Range)
If Target.Address <> "$B$23" Then Exit Sub
Application.ScreenUpdating = False
Columns.Hidden = False
If Target = "" Then Exit Sub
Application.EnableEvents = False
[c50:au50].FormulaLocal = "=EQUIV($B$23;C3:C20;0)"
Range("C50:AU50").SpecialCells(xlCellTypeFormulas, 16).EntireColumn.Hidden = True
Rows(50).Delete
Application.EnableEvents = True
End Sub