opf.Filter = "Word-Dateien(*.doc, *.docx)|*.doc;*.docx";

            if (opf.ShowDialog() == false)
                return;

            //////  set the file name from the open file dialog
            object fileName = opf.FileName;
            object readOnly = false;
            object isVisible = true;
            //////   Here is the way to handle parameters you don't care about in .NET
            object missing = System.Reflection.Missing.Value;

            ////  Make word visible, so you can see what's happening
            WordApp.Visible = true;
            ////  Open the document that was chosen by the dialog
            //Document aDoc = WordApp.Documents.Open(ref fileName, ref missing, ref readOnly, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref isVisible);
            Document aDoc = WordApp.Documents.Open(opf.FileName, ReadOnly: false, Visible: true);
            
            ////  Activate the document so it shows up in front
            aDoc.Activate();

            //// JEe Tabelle im Word-Dokument durchlaufen
            foreach (Table docTbl  in aDoc.Tables)
            {
                //// Jede Row in der Tabelle durchlaufen
                foreach (Row row in docTbl.Rows)
                {
                    //// Erst Zelle der "Row" bereinigen (Texte entfernen)
                    string strTemp = row.Cells[1].Range.Text.Trim();
                    if (strTemp.Contains("\r"))
                        strTemp = strTemp.Replace("\r", "");
                    if (strTemp.Contains("\a"))
                        strTemp = strTemp.Replace("\a", "");

                    //// Suche nach Begriff in Datentabelle
                    DataRow[] rows = ds.Tables[0].Select("F0 = '" + strTemp + ".'");

                    //// Wenn Begriff in DataTable vorhanden, diesen überschreiben
                    if (rows.Length > 0)
                    {
                        //// ==> zwar keine Fehlermeldung, aber die Zelle wird nicht überschrieben, der Text wird davor geklemmt
                        row.Cells[1].Range.Text = rows[0][2].ToString();
                        row.Cells[1].Range.Font.Color = WdColor.wdColorViolet;
                    }

                }
            }