I am not sure how you move the entire list at one time, but this code will loop through the list and save one item at a time. It will also load the data into the listbox.
Code:
Private Sub cmdLoad_Click()
Dim strInputData As String
Listbox1.clear
Open "C:\List.txt" For Input As #1
Do While Not EOF(1) ' Check for end of file.
Line Input #1, strInputData ' Read line of data.
Listbox1.AddItem Trim(strInputData)
Loop
Close #1
End Sub
Private Sub cmdSave_Click()
Dim i As Integer
Open "C:\List.txt" For Output As #1
For i = 0 To Listbox1.ListCount - 1
Print #1, Listbox1.List(i)
Next i
Close #1
End Sub