DataBinding in ComboBox

Question

Hello, I have a ComboBox, which get its values from BindingSource, and gets its current value from another BindingSource. (If it matters, the source of the BindingSource is DataSet). Here is the problem i am facing: i want the combo to present the values, but with exta information that changes from value to value. I want that for strings that are 3 length long, will be showen with extra "!!", and strings with 5 length long will be shown with exta "@@". For example, if this is the content of my DataSet (which connected to the BindingSource): dog, cat, cool, animal so this is how the value would seem to the user: dog!!, cat!!, cool, animal@@ of course i dont want the DataSet behind the BindingSource to be changed.. just for the combo presentation. Thank you very much, Liran.