名流巨星小说结局:VB高级问题

我是个新手对下面的定义我一个也不会，，高手帮帮我呀

他是做带图片的菜单的

Option Explicit

Private Declare Function GetMenu Lib "user32" _
(ByVal hwnd As Long) As Long

Private Declare Function GetSubMenu Lib "user32" _
(ByVal hMenu As Long, ByVal nPos As Long) As Long

Private Declare Function SetMenuItemBitmaps Lib "user32" _
(ByVal hMenu As Long, ByVal nPosition As Long, ByVal wFlags As Long, _
ByVal hBitmapUnchecked As Long, ByVal hBitmapChecked As Long) As Long

Const MF_BYPOSITION = &H400&

Private Sub Form_Load()
Dim mHandle As Long, lRet As Long, sHandle As Long, sHandle2 As Long
mHandle = GetMenu(hwnd)
sHandle = GetSubMenu(mHandle, 0)
lRet = SetMenuItemBitmaps(sHandle, 0, MF_BYPOSITION, imOpen.Picture, imOpen.Picture)
lRet = SetMenuItemBitmaps(sHandle, 1, MF_BYPOSITION, imSave.Picture, imSave.Picture)
lRet = SetMenuItemBitmaps(sHandle, 3, MF_BYPOSITION, imPrint.Picture, imPrint.Picture)
lRet = SetMenuItemBitmaps(sHandle, 4, MF_BYPOSITION, imPrintSetup.Picture, imPrintSetup.Picture)
sHandle = GetSubMenu(mHandle, 1)
sHandle2 = GetSubMenu(sHandle, 0)
lRet = SetMenuItemBitmaps(sHandle2, 0, MF_BYPOSITION, imCopy.Picture, imCopy.Picture)