Here you are:

        private void dgRight_Drop(object sender, DragEventArgs e)
        {
            XamDataGrid dragSource = dgLeft;
            XamDataGrid dragTarget = sender as XamDataGrid;

            //Get Instance of the dragger DataRecordPresenter and DataRecord
            DataRecordPresenter draggedPresenter = e.Data.GetData(typeof(DataRecordPresenter)) as DataRecordPresenter;
            DataRecord draggedRecord = draggedPresenter.Record as DataRecord;


            dragTarget.DataItems.Add(draggedRecord.DataItem);

            MarkAsAdded(draggedRecord);

            sortGrid(dragTarget);
            IsSaved = false;
            btnFormSave.IsEnabled = true;
        }

        private void MarkAsAdded(object p)
        {
            DataRecord addedRecord = (DataRecord)p;

            if (addedRecord.ChildRecords.Count >= 1)
            {
                HighlightChildren(addedRecord.ChildRecords);
            }

            addedRecord.Update();
        }

        private void HighlightChildren(ExpandableFieldRecordCollection efrc)
        {
            foreach (Record r in efrc)
            {
                DataRecord dr = r as DataRecord;
                if (dr != null)
                {
                    dr.Tag = "Bold";
                    DataRowView row = dr.DataItem as DataRowView;
                    if (row != null)
                    {
                        if (row["IsFolder"].ToString() == "True")
                        {
                            dr.Description = "Italic";
                            if (dr.ChildRecords.Count >= 1)
                            {
                                HighlightChildren(dr.ChildRecords);
                            }
                        }
                    }
                }
            }
        }

Thanks,

-Matt.