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
 
Private Const WM_LBUTTONDOWN = &H201
 
Private Sub Command1_MouseDown(Button As Integer, Shift As Integer, X As _
  Single, Y As Single)
   Static m
   Timer1.Enabled = True
   m = m + 1
   Form1.Caption = m
End Sub
 
Private Sub Command1_MouseUp(Button As Integer, Shift As Integer, X As Single, _
  Y As Single)
   Timer1.Enabled = False
End Sub
 
Private Sub Form_Load()
   Timer1.Interval = 100
   Timer1.Enabled = False
End Sub
 
Private Sub Timer1_Timer()
   SendMessage Command1.hwnd, WM_LBUTTONDOWN, 0, ByVal 0&
End Sub