Kontroller om Excel fil er åben

Sub TestFileOpen()
If IsFileOpen("c:\Users\Flj\Desktop\xxx.xlsx") Then
        MsgBox "File already in use!"
    Else
        MsgBox "File not in use!"
        Workbooks.Open ("c:\Users\Flj\Desktop\xxx.xlsx")
    End If
End Sub
Function IsFileOpen(filename As String)
    Dim filenum As Integer, errnum As Integer

    On Error Resume Next
    filenum = FreeFile()
   
    Open filename For Input Lock Read As #filenum
    Close filenum
    errnum = Err
    On Error GoTo 0

    Select Case errnum
        Case 0
        IsFileOpen = False

        Case 70
            IsFileOpen = True

        Case Else
            Error errnum
    End Select

End Function

http://www.EXCELGAARD.dk/Bib/FileStatus/

Sub test()

On Error Resume Next
    Application.Workbooks("Mappe1.xlsx").Activate
    If Err.Number <> 0 Then
   
        MsgBox ("Mappe1 er ikke åben?")
   
    Else
   
        MsgBox ("Mappe1 er åben?")
       
    End If
   
End Sub