FarPoint.Win.Spread.Model.DefaultSheetSpanModel defspanModel = new FarPoint.Win.Spread.Model.DefaultSheetSpanModel();
fpSpread1.ActiveSheet.Models.Span = defspanModel;
defspanModel.Add(0, 0, 2, 2);
string fileName;
fileName = "D:\\Temp\\myser.xml";
System.IO.Stream stream;
stream = System.IO.File.Open(fileName, System.IO.FileMode.Create);
System.Xml.XmlTextWriter writer = new System.Xml.XmlTextWriter(stream, System.Text.Encoding.UTF8);
writer.Formatting = System.Xml.Formatting.Indented;
writer.Indentation = 2;
writer.WriteStartDocument();
writer.WriteStartElement("Span");
defspanModel.Serialize(writer);
writer.WriteEndElement();
writer.WriteEndDocument();
writer.Close();