Private Sub Workbook_Open()
For i = 1 To Sheets.Count
If Sheets(i).Name = "A" Then
If Right(ActiveWorkbook.Name, 5) = ".xlsm" Then
Sheets(i).Name = Left(ActiveWorkbook.Name, Len(ActiveWorkbook.Name) - 5)
Exit Sub
Else
Sheets(i).Name = Left(ActiveWorkbook.Name, Len(ActiveWorkbook.Name) - 4)
Exit Sub
End If
End If
Next i
End Sub