$re = '/([+0]?[06]?)(?&sep)(36)?(?&sep)(?P<aera>1|[2-9][0-9])(?&sep)(?P<num>\d{3})(?&sep)(\d{2})(?\'sep\'[\)\(-\/\.x ]*){2}/i';
$str = '+36 20 800 8848
36 1 267-5260
+36 1 267 5260
+36 24 415 351
06 (24) 415 351
6(1)415 3510
00361-267-5260
0036-1-267-5260
0036-1-267-52-60
208008848
20800 88-48
00 34 800 828
((06)|[\\+0]{0,2}\\s*36)
[+0]{0,2}(?&sep)36';
$subst = "$3$4$5$6";
$result = preg_replace($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