<?php
 
function simpleConvert($from,$to,$amount)
{
	return "USD 999" . $amount;
}
$content = "The following fees and deposits are charged by the property at time of service, check-in, or check-out.\r\n\r\nBreakfast fee: between AUD 9.95 and AUD 20.00 per person (approximately)\r\nFee for in-room wireless Internet: AUD 0.00 per night (rates may vary)\r\nFee for in-room high-speed Internet (wired): AUD 9.95 per night (rates may vary)\r\nFee for high-speed Internet (wired) in public areas: AUD 9.95 per night (rates may vary)\r\nLate check-out fee: AUD 40\r\nRollaway beds are available for an additional fee\r\nOnsite credit card charges are subject to a surcharge\r\nThe above list may not be comprehensive. Fees and deposits may not include tax and are subject to change.";
$pattern_new = '/\bAUD (\d*\.?\d+)/';
$res = preg_replace_callback($pattern_new, function($m) {
	return simpleConvert("AUD","USD",$m[1]);
}, $content);
echo $res;
 
preg_match_all($pattern_new, $content, $vals);
print_r($vals[1]);

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