html tooltip

Hi,

I would like to add some html link to the tooltip.

But I need to add the tooltip in php file, my code in functions.php is like this:

function cw_change_product_price_display( $price ) {
$price .= ' <span class="vatregister tooltips" title="<a href="url">Click here</a>">incl. VAT</span>';
return $price;
}
add_filter( 'woocommerce_get_price_html', 'cw_change_product_price_display' );
add_filter( 'woocommerce_cart_item_price', 'cw_change_product_price_display' );

So how can I make that title tag to contain html?

Thanks!