my @order = ('~', '&', '@', '%', '+', '');
my %order = map { $order[$_] => $_ } 0..$#order;

sub nick_cmp {
   my ($a_p, $a_n) = $a =~ /^([~&\@%+]?)(.*)/s;
   my ($b_p, $b_n) = $b =~ /^([~&\@%+]?)(.*)/s;
   $order{$a_p} <=> $order{$b_p} || lc($a_n) cmp lc($b_n)
}

my @users = qw(
   goodman hsytva %pisyun [error] Gerich Fair
   CYCLER ~shurmann &BECHED sp w %sanekdark
   FIXER lizergin @XUEC
);

print "$_\n"
   for sort nick_cmp @users;
[download]

~shurmann
&BECHED
@XUEC
%pisyun
%sanekdark
[error]
CYCLER
Fair
FIXER
Gerich
goodman
hsytva
lizergin
sp
w
[download]