CModule::IncludeModule('iblock');
$arSelect = Array("ID", "NAME", "CODE");
$arFilter = Array("IBLOCK_ID"=>24, "ACTIVE"=>"Y", "CODE" => "koltso-s-brilliantom-i-izumrudom-208476");
$res = CIBlockElement::GetList(Array(), $arFilter, false, false, $arSelect);
while($arElement = $res->GetNext())
{
    $nn++;
    echo $nn.". <b>".$arElement["ID"]."</b> - ".$arElement["NAME"]." code:".$arElement["CODE"];
    $arFieldsID[] = $arElement["ID"]; // получаем ID нужных элементов
}