$re = '/\|*Admin\|*/im';
$str = '1H|\\^&|||ARCHITECT^8.10^F3453010030^H1P1O1R1C1Q1L1|||Admin||||P|1|20150511083525
1D';
$subst = "|";
$result = preg_replace($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