Private Sub Worksheet_Change(ByVal Target As Range)

Select Case Target.Address

Case "$A$1"

If Not IsNumeric(Target.Value) Or Target.Value = "" Then

Exit Sub

Range("B1:B9").Copy Range("B2")

Range("B1").Value = Range("A1").Value

Target.Select

End Select

End Sub

このコードの意味教えてくださいー