var sectionDocument = new GrapeCity.ActiveReports.Document.SectionDocument();
sectionDocument.Load("Document.rdf");
sectionDocument.Printer.PrinterName = "TheNetworkPrinterName";
sectionDocument.Printer.Landscape = true;
//To call the Print method, add a reference to Viewer.Win or Viewer.WPF
sectionDocument.Print();

var sectionReport = new GrapeCity.ActiveReports.SectionReport();
using (var reader = new System.Xml.XmlTextReader("Report.rpx"))
{
	sectionReport.LoadLayout(reader, out System.Collections.ArrayList error);
}
sectionReport.Document.Printer.PrinterName = String.Empty;
viewer.LoadDocument(sectionReport);