How to automate filtering in RadComboBox

Telerik RadComboBox has an Input Area control, which displays the selected item. Depending on the RadComboBox properties, the user can use this area to type in a new value and hence enables filtering. I need to automate entering a value in input area and verify that the item is returned/highlighted.

I'm able only to identify the input area control. How do I automate the entering of the combobox item programmatically in Telerik test framework?.. Here is how I find the controls. Could someone help?

var comboBox = broker.Find<RadComboBox>(Reference);
var inputArea= comboBox.Find.ByAutomationId<TextBox>("PART_EditableTextBox");
            textBox.Text = Data;