I found a solution. I disabled column sorting, and used the CellClick event as follows:
private void radGridView1_CellClick(object sender, GridViewCellEventArgs e){ if (e.Row is GridViewTableHeaderRowInfo) { Telerik.WinControls.UI.GridHeaderCellElement ghce= (Telerik.WinControls.UI.GridHeaderCellElement)sender; Telerik.WinControls.UI.GridViewTemplate gwt = (Telerik.WinControls.UI.GridViewTemplate)ghce.ViewTemplate; var ChildSort = new Telerik.WinControls.Data.SortDescriptor() { PropertyName = e.Column.Name , Direction = System.ComponentModel.ListSortDirection.Ascending }; var ChildSort2 = new Telerik.WinControls.Data.SortDescriptor() { PropertyName = "sortorder", Direction = System.ComponentModel.ListSortDirection.Ascending }; gwt.SortDescriptors.Clear(); gwt.SortDescriptors.Add(ChildSort2); gwt.SortDescriptors.Add(ChildSort); }}