Const MF_BYPOSITION=&H400&
API's GetMenu, GetSubMenu, SetMenuItemBitmaps
Private Sub Form_Load()
Dim menu As Long, submenu As Long
menu = GetMenu(Me.hwnd)
If menu=0 Then
  MsgBox "No hay menu"
  End
End If
submenu = GetSubMenu (menu, 0)
If submenu=0 Then
  MsgBox "No hay submenu"
  End
End If
SetMenuItemBitmaps submenu, 0, MF_BYPOSITION, Pic1.Picture, Pic1.Picture
End Sub