$re = '/(?:\s)*<task action="4" id="94(\d\d\d)00(\d\d)">(?:\s)*<release>(?:\s)*<item type="cost" vitality="\d"(?:\s)*\/>((?:\n|.)*?)<item type="param(?:(?:\n|.)*?)(?=<\/win)((?:\n|.)*?)<\/release>(?:\s)*<\/task>(?:\s)*/m';
$str = ' <task action="4" id="941010010">
<release>
<item type="cost" vitality="1" />
<item type="fight" npcid="1010010">
<win>
<item type="aside" content="[color=#ff7e53]你胜利了![/color]" auto="true" />
<item type="random">
<item probability="0.001">
<item type="reward" yueli="300" money="100" auto="true">
<item id="2801" num="1" />
</item>
</item>
<item probability="0.001">
<item type="reward" yueli="300" money="100" auto="true">
<item id="2901" num="1" />
</item>
</item>
<item probability="0.001">
<item type="reward" yueli="300" money="100" auto="true">
<item id="3001" num="1" />
</item>
</item>
<item probability="0.001">
<item type="reward" yueli="300" money="100" auto="true">
<item id="3101" num="1" />
</item>
</item>
</item>
<item type="param" key="fight-1010010" action="update" value="1" />
</win>
<lose>
<item type="aside" content="[color=#ff7e53]你被{rnpc}打倒在地![/color]" auto="true" />
</lose>
</item>
</release>
</task>';
$subst = "\n\n\n\n<stroy id=\"$17$2\" areaid=\"0\" startid=\"-1\" endid=\"-1\" maxnum='0' interval='0' count=\"0\" type='3'>$3$4</stroy>\n\n";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$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