$re = '/^(\s\w|\s\s)\s{2}(\w{2}\d{2}PRI)((?:\s+\d+)+)/m';
$str = ' Device FT01PRI FT02PRI FT03PRI FV01PRI FV02PRI
F AD01PRI 0 0 0 0 0
R CX01PRI 0 3 0 3 6
O CX02PRI 2 2 1 0 0
M CX03PRI 2 0 1 1 6
DA01PRI 0 0 0 0 0
DA02PRI 6 0 0 0 0
DB01PRI 0 0 0 0 0 ';
$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