In the following, I am trying to persist a set of objects in an excel worksheet. Each time the function is called to store a value, it should allocate the next cell of the A column to store that object.

However, an exception is thrown by the Interop library on the first call to get_Range(). (right after the catch block)

Does anyone know what I am doing wrong?

private void AddName(string name, object value)
        {
            Excel.Worksheet jresheet;
            try
            {
                jresheet = (Excel.Worksheet)_app.ActiveWorkbook.Sheets["jreTemplates"];
            }
            catch
            {
                jresheet = (Excel.Worksheet)_app.ActiveWorkbook.Sheets.Add(Type.Missing, Type.Missing, 
                                                                       Type.Missing, Type.Missing);
                jresheet.Visible = Microsoft.Office.Interop.Excel.XlSheetVisibility.xlSheetVeryHidden;
                jresheet.Name = "jreTemplates";
                jresheet.Names.Add("next", "A1", true, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            }
            Excel.Range cell = jresheet.get_Range("next", Type.Missing);
            cell.Value2 = value;
            string address = ((Excel.Name)cell.Name).Name;
            _app.ActiveWorkbook.Names.Add(name, address, false,
                                      Type.Missing, Type.Missing, Type.Missing, Type.Missing, 
                                      Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            cell = cell.get_Offset(1, 0);
            jresheet.Names.Add("next", ((Excel.Name)cell.Name).Name, true, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
        }