Unfortunately, I've already got that set. The grid is declared
<telerik:RadGrid ID="RadGrid_CM" runat="server" AllowSorting="true" AllowPaging="true" PageSize="25" AllowFilteringByColumn="false"
OnDataBinding="RadGrid_CM_DataBinding" OnItemCommand="RadGrid_CM_ItemCommand"
OnItemDataBound="RadGrid_CM_ItemDataBound"
ShowStatusBar="false" Skin="Simple" Width="100%">
<MasterTableView DataKeyNames="ID" AutoGenerateColumns="false" Width="100%" CommandItemDisplay="Top" NoMasterRecordsText="No Results found.">
<Columns>
...
</Columns>
<CommandItemSettings ShowAddNewRecordButton="false" ShowRefreshButton="false" ShowExportToWordButton="false" ShowExportToExcelButton="true" ShowExportToCsvButton="false" />
</MasterTableView>
</telerik:RadGrid>
and then in the code behind
grid.ExportSettings.FileName = FileName + DateTime.Now.ToString("yyyyMMdd");
grid.MasterTableView.CommandItemDisplay = GridCommandItemDisplay.None;
grid.GridLines = GridLines.Both;
grid.MasterTableView.AllowFilteringByColumn = false;
grid.MasterTableView.AllowSorting = false;
grid.ExportSettings.ExportOnlyData = true;
grid.ExportSettings.IgnorePaging = true;
grid.ExportSettings.OpenInNewWindow = true;
grid.CurrentPageIndex = 0;
grid.PageSize = int.MaxValue;
grid.DataSource = null;
grid.Rebind();
grid.MasterTableView.ExportToExcel();