$re = '/^I(?:\|[^|]*){20}(\d{3}-\d{6})/m';
$str = 'T|112|| | | |AZ |D |1 | 1|
I| 10|ACAA |BY CORD EACH | 10.00-| .99 | | .36 |1 | 1|D |I|CO |BTE |N| | .00 | .00 |15 |1 |001-123456 |ACAA
I| 20|LEES03 |TINTED OZ | 2.00-| 6.50 | | 4.48 |1 | 1|D |I|FL |LTGE |N| | .00 | .00 |45 |1 |001-234555 |JEE
I| 20|LEES03 |TINTED OZ | 2.00-| 6.50 | | 4.48 |1 | 1|D |I|FL |LTGE |N| | .00 | .00 |45 |1 | |JEE
I| 20|LEES03 |TINTED OZ | 2.00-| 6.50 | | 4.48 |1 | 1|D |I|FL |LTGE |N| | .00 | .00 |45 |1 |001-234552 |JEE ';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
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