or
provider.AggregateDescriptions.Add(
new PropertyAggregateDescription()
{ PropertyName = "remaining", CustomName = "Остаток", AggregateFunction = AggregateFunctions.Average }
);

namespace sample{ class foo { public int ID { get; set; } public string Name { get; set; } public string Desc { get; set; } private List<bar> _customFields; public foo () { _customFields = new List<bar>(); } } class bar { public string FieldName { get; set; } public string Value { get; set; } }}
((Telerik.WinControls.UI.RadPageViewLabelElement)(this.radPageView1.GetChildAt(0).GetChildAt(1))).Text = "Test";

