You can use any XML format to populate RadMenu with
data. This example shows how you can load your XML file into XmlDocument
and use the API of RadMenu and XmlDocument to
create a hierarchical menu.
If your XML is static and will not change, an even easier way is to use the
built-in Visual Studio.NET designer - its convenient desktop user interface
allows you to customize your menu and the result is saved inline in the
ASPX page.