如何修改右鍵彈出的菜單的內容

CMenu menu;

ClientToScreen(&point);

VERIFY( menu.LoadMenu( IDR_MENU1 ) );

CMenu* popup = menu.GetSubMenu(0);

ASSERT( popup != NULL );

popup->EnableMenuItem(ID_POPUP1, MF_BYCOMMAND|MF_GRAYED);

popup->ModifyMenu(ID_POPUP1,MF_BYCOMMAND,ID_POPUP1, "11");

popup->TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON, point.x, point.y, this );