- preg_match_all: documentation ( source)
<?php
$regex = '/<!--.*? ([\d\.]+)/s';
$string = '<!--Version 5.2 Vehicle Selling Price added to contracting request-->
<!--Version 5.1.1 Fixed issue with EX1DealStatus, see PRO-940-->
<!--Version 5.1 Added form fields complex type to rate response, s';
preg_match_all($regex,$string,$o);
echo $string[1][0];