Hi,
There is not one function to easily do that. You can do something like that:
//$element is either a object of the information of a product from the product table or an array of these same objects.
//$ids is an array of all the ids of the $element variable
$currency_id = hikashop::getCurrency();
$config =& hikashop::config();
$main_currency = $config->get('main_currency');
$zone_id = hikashop::getZone();
$discount_before_tax = $config->get('discount_before_tax');
$currencyClass = hikashop::get('class.currency');
$currencyClass->getPrices($element,$ids,$currency_id,$main_currency,$zone_id,$discount_before_tax);
That will set the prices with discounts and conversion of currency.