Using a variable range to add subtotals to columns

[mindbender]

I have the following script in my spreadsheet that loops through a folder and then applies bolding and subtotals to each spreadsheet within the folder.

With the reports containing information by day, the number of columns to subtotal will be different each day. I am wondering if there is a way instead of saying TotalList:=Array(4,5) if there is a way to look at the number of columns and update all present in the spreadhseets.

I hope I am making sense and look forward to your advice

Sub Example()
    Dim MyPath As String, FilesInPath As String
    Dim MyFiles() As String, Fnum As Long
    Dim mybook As Workbook
    Dim CalcMode As Long
    Dim sh As Worksheet
    Dim ErrorYes As Boolean
    Dim rng As Range
    Dim cell As Range
    'Fill in the path\folder where the files are
    MyPath = "C:\Temp"
    'Add a slash at the end if the user forget it
    If Right(MyPath, 1) <> "\" Then
        MyPath = MyPath & "\"
    End If
    'If there are no Excel files in the folder exit the sub
    FilesInPath = Dir(MyPath & "*.xl*")
    If FilesInPath = "" Then
        MsgBox "No files found"
        Exit Sub
    End If
    'Fill the array(myFiles)with the list of Excel files in the folder
    Fnum = 0
    Do While FilesInPath <> ""
        Fnum = Fnum + 1
        ReDim Preserve MyFiles(1 To Fnum)
        MyFiles(Fnum) = FilesInPath
        FilesInPath = Dir()
    Loop
    'Change ScreenUpdating, Calculation and EnableEvents
    With Application
        CalcMode = .Calculation
        .Calculation = xlCalculationManual
        .ScreenUpdating = False
        .EnableEvents = False
    End With
    'Loop through all files in the array(myFiles)
    If Fnum > 0 Then
        For Fnum = LBound(MyFiles) To UBound(MyFiles)
            Set mybook = Nothing
            On Error Resume Next
            Set mybook = Workbooks.Open(MyPath & MyFiles(Fnum))
            On Error GoTo 0
            If Not mybook Is Nothing Then

                'Change cell value(s) in one worksheet in mybook
                On Error Resume Next
                With mybook.Worksheets(1)
                    If .ProtectContents = False Then
                    
                    ActiveSheet.Range("1:1").Font.Bold = True
                    ActiveSheet.Range("1:1").EntireColumn.AutoFit
                     
                    Selection.Subtotal GroupBy:=2, Function:=xlSum, TotalList:=Array(4, 5)
                    Else
                        ErrorYes = True
                    End If
                End With

                If Err.Number > 0 Then
                    ErrorYes = True
                    Err.Clear
                    'Close mybook without saving
                    mybook.Close savechanges:=False
                Else
                    'Save and close mybook
                    mybook.Close savechanges:=True
                End If
                On Error GoTo 0
            Else
                'Not possible to open the workbook
                ErrorYes = True
            End If
        Next Fnum
    End If
    If ErrorYes = True Then
        MsgBox "There are problems in one or more files, possible problem:" _
             & vbNewLine & "protected workbook/sheet or a sheet/range that not exist"
    End If
    'Restore ScreenUpdating, Calculation and EnableEvents
    With Application
        .ScreenUpdating = True
        .EnableEvents = True
        .Calculation = CalcMode
    End With
End Sub