Private Sub fillList(index As Integer)
    List1.Clear
    List1.AddItem "Test 1"
    List1.AddItem "Test 2"
    List1.AddItem "Test 3"
    List1.AddItem "Test 4"
    List1.AddItem "Test 5"
    List1.AddItem "Test 6"
    List1.AddItem "Test 7"
    List1.AddItem "Test 8"
    List1.ListIndex = index
End Sub
 
Private Sub Form_Load()
    fillList 0
End Sub
 
Private Sub List1_DblClick()
    MsgBox List1.Text
    fillList List1.ListIndex
End Sub