there is no trick but it might give you not the correct result :)
1. Search on UIItem seems to be descendent search so all elements will be found not only direct children (AutomationElement.FindAll(TreeScope.Descendent, ....) if you use UIAutomation without white.
2. But if there are several Label with the same id you will get only the first one.
Other way for WPF => IUIItem labels =row
works only on Standdard White Controls and only if using White.Core.UIItems.WPFUIItems; is used