Apply Programmatic Custom Sorting Automatic RadGridView/RadTreeListView?

[Jordi]

I can sort columns programmatic like the example in documentation using ColumnSortDescriptors
http://www.telerik.com/help/wpf/gridview-sorting-programmatic.html
Also I have a Custom Sorting defined using the GridView Sorting event:
this.radGridView.Sorting += this.radGridView_Sorting; 
http://www.telerik.com/help/wpf/gridview-sorting-custom.html
This event only is fired when the user click in the column header it's not fired automatic. How can Sort automatic?

Thank you.