Not sure the Title gives anything away there like!

I have a userform containing 1 list box which the user can select multiple items from in addition I have 3 fields below that where users can add new items (the idea being, if they're not in the list then add them). The list will only be used once so they dont need to be saved for future use, simply need to be in the listbox and selected once the user hits the "Finish" button.

ie

Listbox contains 5 items
Apple
Pear
Banana
Cherry
Strawberry

The user selects Pear and Cherry, they also however want to add in Blueberry so they complete the field below and hit "Add"

system then adds Blueberry to the listbox and selects it so there are now 6 items listed of which 3 are selected.

Is that possible?