Get the number of CountItems by group in CS5 extended

I have a collection of photos with count items created with the Count Tool in CS5 extended version. Each count item belongs to one of 5 count groups created with the Count Tool. Using the Photoshop COM, I can get the total number of count items per photo (Document.CountItems.Count()). However, I cannot get the number of count items per count group, or the group a count item belongs to. Has anybody had success in accessing count groups? I am using C#, but a solution in any language would be helpful.