It seems that this is a duplicate of an existing request: http://feedback.telerik.com/Project/154/Feedback/Details/111835-add-support-for-the-excel-group-rows-feature-when-exporting-data-from-radgridvie. Please use the alternative link instead.
This would be a great addition to the radgridview. It can be either on the groups if you allow your grid to be grouped or on hierarchical structure. http://www.c-sharpcorner.com/UploadFile/f201d9/data-export-to-excel-and-create-group-report-in-net3/ http://www.e-iceblue.com/Knowledgebase/Spire.XLS/Demos/Group/EXCEL-Group-for-C-VB.NET.html