Add icon to next to GroupsOrder caption

I have a Report control that I have grouped per a specific column. I see that the caption of the GroupsOrder is a combination of the column name and the text of the record item from that row. I'd like to add an icon to the left of the caption for the grouping. Is that possible? I've tried a number of different techniques but cannot seem to make it occur. As well, I see no samples in the samples folder that shows how to do this.