How to add a field object to group header section in crystal report document?

Hi All, I have got two questions mentioned below, please share your inputs. 1)I want to know whether it is possible to add a field object to header section in crystal report document programmatically? I am using crystal runtime for visual studio. I know that using RAS we can do it, but I want to do it using managed library of crystal runtime. Please suggest. 2) I am doing a POC where I am using RAS (unmanaged library) to manipulated crystal report document. Please see code below: var dbTable = _reportDocument.ReportClientDocument.DatabaseController.Database.Tables[0]; var dbField = dbTable.DataFields.FindField(item.ColumnName,                         CrystalDecisions.ReportAppServer.DataDefModel.CrFieldDisplayNameTypeEnum.crFieldDisplayNameName,                         CrystalDecisions.ReportAppServer.DataDefModel.CeLocale.ceLocaleEnglishUS); CrystalDecisions.ReportAppServer.ReportDefModel.FieldObject fieldObject = new CrystalDecisions.ReportAppServer.ReportDefModel.FieldObject();                     fieldObject.DataSourceName = dbField.Name;                     fieldObject.FieldValueType = dbField.Type; var groupHeaderArea = _reportDocument.ReportClientDocument.ReportDefController.ReportDefinition.GroupHeaderArea[0].Sections[i]; _reportDocument.ReportClientDocument.ReportDefController.ReportObjectController.Add(fieldObject, groupHeaderArea); In above code last line throwing exception : "The report field type is not valid." at CrystalDecisions.ReportAppServer.Controllers.ReportObjectControllerClass.Add(ISCRReportObject ReportObject, Section Section, Int32 nIndex) Thanks, Jai