If you gooing to make an instance variable for each multiplicator for each character, thats gonna be a lot of events.
Suggestion, make a second list holding all the multiplicators in the same order as the characters.
If you name that second list 'Mult', then the calculation =
int(CPBox.Text) * int(Mult.ItemTextAt(List.SelectedIndex))
One line of code for any selection and any value input.
Do you know as well how I can round up the number? 1321.34 to 1321