Copy Sheet and Macro without linking to old sheet

Hi,

With a macro I copy a sheet out of the workbook and create a new one.
I then want this new sheet to have the following macro:

Private Sub Mail()

    Dim olApp As Outlook.Application
    Dim olMail As Outlook.MailItem
    
    On Error Resume Next
    Set olApp = GetObject(, "Outlook.Application")
    If Err.Number <> 0 Then
        Set olApp = CreateObject("Outlook.Application")
        Err.Clear
    End If
    On Error GoTo 0
    
    Set olMail = olApp.CreateItem(olMailItem)
    
    With olMail
        .Subject = Range("A1") & " " & Range("A3")
        .To = Range("A8")
        .CC = Range("A9")
        .Attachments.Add ThisWorkbook.FullName
        .Display
    End With

End Sub

Until now I have a userform that gets copied as well.
But it will then refer to and also attach the old workbook, how can I change that ? Since the new workbook has a naming policy (date, name etc) it's never the same and cannot be used directly.