How to retrieve imported shapefile attribute values that are shown as Item Type properties but no item type library is created by the import?

HI - I have imported a shapefile into Microstation and I can see its attribute values under an Item Type whose name is the same as the imported shapefile. However, this Item Type is not shown under any Item Type library in the Item Types dialog. How do I read an element's imported attribute values in this scenario using the C# API?

Thanks,

Martin