DropdownList / ComboBox controls in CUI defined toolbars?

I am trying to create a toolbar where the user can select from a list (and ideally a graphic for every list entry), and the selection remains visible in the display (like for example in the Layer Controls)

Is there any way to use such controls (dropdown lists / comboboxes) in CUI?

I know about Flyouts, the problem is that our users wouldn't know how to create bitmaps, and a text is more intuitive.

Regards,

Christian Wendt