static void Main(string[] args)
 {
     using (var app = Excel.BlankWorkbook())
     {
         var book  = app[1];
         var sheet = book[1];
         sheet["A1"].Value     = 100;
         sheet["B1"].Value     = "Test String";
         app[1][1][1, 1].Value = 100;
         app.Visibility        = AppVisibility.Visible;
     }
 }