Прокрутка текстка колесиком мышки

int i=...;
Memo->SelStart= i;

//unit.h:
 
#ifndef WM_MOUSEWHEEL
#define WM_MOUSEWHEEL                   0x020A
#endif
//...
public:                       // User declarations
  __fastcall TForm1(TComponent * Owner);
  void __fastcall OnWheel(TMessage &msg);
 
BEGIN_MESSAGE_MAP
MESSAGE_HANDLER(WM_MOUSEWHEEL,TMessage,OnWheel)
END_MESSAGE_MAP(TForm)
 
// unit.cpp:
 
void __fastcall TForm1::OnWheel(TMessage &msg)
{
  //...
}

//---------------------------------------------------------------------------
void __fastcall TForm1::FormMouseWheel(TObject *Sender, TShiftState Shift, int WheelDelta,
          TPoint &MousePos, bool &Handled)
{
 
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormMouseWheelDown(TObject *Sender, TShiftState Shift, TPoint &MousePos,
          bool &Handled)
{
 
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormMouseWheelUp(TObject *Sender, TShiftState Shift, TPoint &MousePos,
          bool &Handled)
{
 
}
//---------------------------------------------------------------------------