Sub test()
Dim strWorkbookname As String
strWorkbookname = "test.xlsx"
If IsWorkbookOpen(strWorkbookname) Then
Call MsgBox("Mappe '" & strWorkbookname & "' ist geöffnet.", vbInformation)
Else
Call MsgBox("Mappe '" & strWorkbookname & "' ist NICHT geöffnet.", vbInformation)
End If
End Sub
Public Function IsWorkbookOpen(Workbookname As String) As Boolean
Dim wkb As Excel.Workbook
On Error Resume Next
Set wkb = Workbooks(Workbookname)
IsWorkbookOpen = Not wkb Is Nothing
End Function