Attribute VB_Name = "Module1"
Sub Macro1()
Attribute Macro1.VB_Description = "checkSUM•ÏŠ·"
Attribute Macro1.VB_ProcData.VB_Invoke_Func = "a\n14"
'
' Macro1 Macro
' checkSUM•ÏŠ·
'
' Keyboard Shortcut: Ctrl+a
'
    LastRow = Range("A1").End(xlDown).Row
    For Row = 1 To LastRow
        orgStr = Range("A" & Row)
        orgChk = Right(orgStr, 2)
        newStr = Left(orgStr, Len(orgStr) - 2)
        If orgChk = "00" Then
            newChk = "FF"
        Else
            newChk = Hex(Val(("&h" & orgChk) - 1))
            If Len(newChk) = 1 Then
                newChk = "0" & newChk
            End If
        End If
        Range("A" & Row) = newStr & newChk
    Next
    
    

End Sub