- preg_replace: documentation ( source)
<?php
$s = array("@^.@", "@.@");
$r = array("Х", "*");
$fam = "Перегудов";
$fam = preg_replace($s, $r, $fam);
//$fam = preg_replace("@^.@e", "", $fam);
//$fam = preg_replace("@.@e", "-", $fam);
echo $fam;
//echo preg_replace($s, $r, $fam);