my $u = 'http://adserver.adtech.de/?addyn|2.0|323|91793|1|277|target=_blank';
print "$u\n";
$u =~ s/(.*\|.*\|.*\|.*\|.*\|).*(\|.*)/${1}976$2/;
print "$u\n";
__END__
http://adserver.adtech.de/?addyn|2.0|323|91793|1|277|target=_blank
http://adserver.adtech.de/?addyn|2.0|323|91793|1|976|target=_blank

##</code><code>##

my $u = 'http://adserver.adtech.de/?addyn|2.0|323|91793|1|277|target=_blank';
print "$u\n";

my @fields = split /\|/, $u;
$fields[5] = 976;
$u = join '|', @fields;

print "$u\n";
__END__
http://adserver.adtech.de/?addyn|2.0|323|91793|1|277|target=_blank
http://adserver.adtech.de/?addyn|2.0|323|91793|1|976|target=_blank