Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Const LB_ITEMFROMPOINT = &H1A9
Private Sub Form_Load()
List1.AddItem "111"
List1.AddItem "222"
List1.AddItem "333"
List1.AddItem "444"
End Sub

Private Sub List1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim lXPoint As Long
Dim lYPoint As Long
Dim lIndex As Long
If Button = 0 Then
lXPoint = CLng(X / Screen.TwipsPerPixelX)
lYPoint = CLng(Y / Screen.TwipsPerPixelY)
With List1
lIndex = SendMessage(.hwnd, LB_ITEMFROMPOINT, 0, ByVal _
((lYPoint * 65536) + lXPoint))
If (lIndex >= 0) And (lIndex <= .ListCount) Then
' .List(lIndex) contains the name of the item under the mouse cursor.
' if you want to display the item in textbox, simply write:
' Text1.Text =.List(lIndex)
.ToolTipText = .List(lIndex)
Else
.ToolTipText = ""
End If
End With
End If
End Sub