Multiple currency selector: converting the clone price only?

Question

I allow users to select their own currency to see a product price. But I want them always pay the cart by Base Currency which is Euro.

It is just like this store, where you can see the currency you select in in parentheses, next to the Base Currency (euro),

Is it possible to achieve that in Magento 1.8?

This is the code of my currency selector.

<?php if($this->getCurrencyCount() > 1): ?>
<div class="form-micro">

    <select onchange="window.location.href=this.value" name="custom-currency-selector" id="custom-currency-selector">
        <?php foreach ($this->getCurrencies() as $_code => $_name): ?>
        <option value="<?php echo $this->getSwitchCurrencyUrl($_code)?>"
            <?php if($_code == $this->getCurrentCurrencyCode()): ?>
                selected="SELECTED"
            <?php endif; ?>>
            <?php echo $_name ?> <?php echo Mage::app()->getLocale()->currency($_code)->getSymbol() ?>
        </option>
        <?php endforeach; ?>

    </select>
</div>
<?php endif; ?> 

The problem with this is that it changes the Base Currency (euro) that you should pay on checkout to the currency you selected, for instance pounds.

So, I just though whether I can clone the price and the currency selector only converts the clone price without converting the original/ base price (in euro)?

<?php echo $this->getPriceHtml($_product) ?>
<?php echo $this->getPriceHtml($_product, false, '_clone') ?>

Is it possible?