Manually capture an object map item or a locator using the Identify Object dialog box. Using the Identify Object dialog box enables you to identify objects that you want to test with ease and certainty.
/WPFWindow[@caption='Basic Controls'][1]//WPFRichTextBox[@automationId='editableTextBox']
.WPFRichTextBox("@automationId='editableTextBox'").Select(1,10)