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private void btn2_Click(object sender, EventArgs e)
        {
            
            //Benennung der TextBox-Inhalte
            string kmit = txtBox1.Text;
            string nmit = txtBox2.Text;
            int tnmit = Convert.ToInt32(txtBox3.Text);
            int fnmit = Convert.ToInt32(txtBox4.Text);
            int zNr = lstBox1.SelectedIndex;
            string miAlt = lstBox1.Items[zNr].ToString();
            StreamWriter schleife = new StreamWriter(@"T:\transfer\hes\templates\mitarbeiter2.csv", true);
            
            System.Collections.IEnumerator entryItr = lstBox1.Items.GetEnumerator();
            while (entryItr.MoveNext())
            {
                string entry = entryItr.Current.ToString();
                if (entry != miAlt)
                {
                    schleife.WriteLine(entry);
                }
                else
                {
                    string ersatz = Regex.Replace(entry, miAlt, kmit + ";" + nmit + ";" + ";" + tnmit + ";" + fnmit);
                    schleife.WriteLine(ersatz);
                }
            }
            schleife.Close();

            string path = @"T:\transfer\hes\templates\mitarbeiter.csv";
            string path2 = @"T:\transfer\hes\templates\mitarbeiter2.csv";

            if (!File.Exists(path))
            {                
                using (FileStream fs = File.Create(path)) { }
            }

            
            if (File.Exists(path2))
                File.Delete(path2);

            
            File.Move(path, path2);

        }