Merge multiple report document to one report document in c#

Hi all,
 i have been printing all the report document seperately like this
 ReportDocument docBDSheet = objIssuerSvc._IssuerPackageDTCLetter_BrokerDealerSheet;
 docBDSheet.PrintToPrinter(1,false,0,0);
say this report document print 4 pages..,i have multiple report document lk this,is their any way to add a report document of 8 pages to the current report document ,i need to print all the report document in a single button click.. is their any way to merge all the report document to a single report document? so that i will set the merged report document as a source to crystal report and i will print it as explained earlier!!.. please anyone help !!!