You usually need to put more information to list boxes, combo boxes, etc. Not only in this case. Moreover, the data shown as strings presented in the list items should not be considered as good input data.
You should use the simple fact: the items don't have to be strings. In your case, they should not be. You need to develop a comprehensive data type used to represent the elements of the list. How? Please see my past answers:
combobox.selectedvalue shows {} in winform[
^],
Windows Form ListBox Selections[
^].
Also note that working with strings representing data instead of data itself is a big fallacy of many beginners these days. Try to avoid it.
—SA