One event that is noticably lacking from VB controls is a MouseOut event. The code below lets you create one. Please note that you need to change the hWnd that is checked in the tmrMouse_Timer() event to the control you want to monitor hovering over.

Add a timer to the form, called tmrMouse. Set its interval to 100. Also, add a command button called cmdHover.

'// VB Web Code Example
'// www.vbweb.co.uk
Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
Private Declare Function WindowFromPoint Lib "user32" (ByVal xPoint As Long, ByVal yPoint As Long) As Long
Private Type POINTAPI
        X As Long
        Y As Long
End Type
Private bHovering As Boolean
Private Sub MouseOut()
    cmdHover.Caption = "Move Mouse Here"
    bHovering = False
End Sub

Private Sub cmdHover_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
    If bHovering = False Then
        '// this event occurs a lot.
        '// only change the caption when we need to
        bHovering = True
        cmdHover.Caption = "Hovering..."
    End If
End Sub

Private Sub tmrMouse_Timer()
    Dim lpPos As POINTAPI
    Dim lhWnd As Long
    '// get the current pos
    GetCursorPos lpPos
    '// see if the mouse is currently over our form
    lhWnd = WindowFromPoint(lpPos.X, lpPos.Y)
    '// if it isn't over the button, then call the MouseOut procedure
    If lhWnd <> cmdHover.hWnd And bHovering = True Then MouseOut
End Sub