It seems, calling "throw new CException('ECurrencyHelper','Unsupported currency type')" - does not work.

Really urgent!
Have my website down for this reason

The Google Finance APIs are no longer available. Thank you for your interest.
my solution:
protected $google = 'https://www.google.com/finance/converter?a={AMOUNT}&from={FROM}&to={TO}';
protected function googleConvert($from, $to, $amount)
{
$uri = str_replace(
array('{FROM}', '{TO}', '{AMOUNT}'),
array($from, $to, $amount), $this->google);
$raw = $this->_request($uri);
$raw = explode("",$raw);
$raw = explode("",$raw[1]);
$converted_amount = preg_replace("/[^0-9.]/", null, $raw[0]);

    return trim($converted_amount) !== ""? (float) $converted_amount : false;
}