$re = '/^ {2}(\d*) *<\? *(\d\.\d{2}) *- *\(multi\) */';
$str = ' 0 <? 0.00 - (multi) Salt';
$subst = "\1,\2,multi,";
$result = preg_replace($re, $subst, $str, 1);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php