This code in a command button click event shows how to manipulate a multiselected items in a listbox.
ListBox: List1/properties/other/multiselect: Simple or Extended(using ctrl-click to select more items)
Private Sub cmdList_Click()
Dim i As Integer
Debug.Print List1.ItemsSelected.Count
For i = 0 To List1.ItemsSelected.Count - 1
Debug.Print List1.ItemsSelected(i) ' index of selected item
Debug.Print List1.ItemData(List1.ItemsSelected(i)) ' value of item selected
Next
End Sub