type
  TForm1 = class(TForm)
    ApplicationEvents1: TApplicationEvents;
    procedure ApplicationEvents1Message(var Msg: tagMSG; var Handled: Boolean);
  private
    FLastCtrl: HWND;
    FLastTick: DWORD;
    FClickCnt: Integer;
  end;

implementation

procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG; var Handled: Boolean);
begin
  if Msg.message = WM_LBUTTONDOWN then
  begin
    // if the same control as before was "left mouse button down-ed", then...
    if (Msg.hwnd = FLastCtrl) then
    begin
      // if 1 second elapsed (1000 here is 1000 ms), then...
      if (GetTickCount - FLastTick >= 1000) then
      begin
        // if the user "left mouse button down-ed" at least 3 times the same control in one second, then...
        if FClickCnt >= 3 then
          // somone clicked the same control at least 3 times per second
        // count this click (it is after that elapsed 1 second period)
        FClickCnt := 1;
        // and store this tick
        FLastTick := GetTickCount;
      end
      // the period of 1 second did not yet elapsed, so let's just increase the click counter
      else
        Inc(FClickCnt);
    end
    else
    begin
      // count this click, store this control handle and this tick
      FClickCnt := 1;
      FLastCtrl := Msg.hwnd;
      FLastTick := GetTickCount;
    end;
  end;
end;