How to create Dual Listbox which copies/remove items on selection and button press?

Hi, here below we have my two beautiful independant listboxes.

The first listbox contains all the items while the second listbox should only store those I choose.

For that, I need to copy the items from Listbox 1 to Listbox 2, then call those copied items in some other function (I'm trying to be general here).

For example, Listbox 1 has A, B, C, D and E and I would like Listbox to display A, D and E when I select the items (can be 1 at a time or multiple at once, whatever is feasible).

My obvious question is : How would I do that?