$re = '/<Interceptor>(.*)\<ActionDate\>2-04-24\<\/ActionDate\>(.*)\<RecordNotes\>test\<\/RecordNotes\>(.*)\<\/Interceptor\>/';
$str = '<Interceptor> <AttackCoords>-423423445345345.10742916222947</AttackCoords> <Outcome>2</Outcome> <Infiltrators>20</Infiltrators> <Enforcer>2</Enforcer> <ActionDate>2-04-24</ActionDate> <ActionTime>00:2:00</ActionTime> <RecordNotes>test</RecordNotes> <NumEscaped>0</NumEscaped> <LaunchCoords>-222222</LaunchCoords> <AttackVessel>111</AttackVessel> </Interceptor>';
$subst = "<Interceptor\>\<ActionDate\>2-04-24\<\/ActionDate\>\<RecordNotes\>test\<\/RecordNotes\>\<\/Interceptor\>";
$result = preg_replace($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