use DBI;
use CGI;
my $cgi = new CGI;
...
while ( my @dsnum = $sth->fetchrow_array )     # Zugriff auf DB Werte
{<a href=\"../cgi-bin/skript2.pl?param0=$dsnum[1]&param1=$dsnum[2]&param2=$dsnum[3]&param3=$dsnum[4]&param4=$dsnum[5]&param5=$dsnum[6]&param6=$dsnum[7]&param7=$dsnum[8]&param8=$dsnum[0]\">aendern</a>}

my $name = $cgi->param('param0');
my $kategorie = $cgi->param('param1');
my $unterkategorie = $cgi->param('param2');
my $benutzer = $cgi->param('param3');
my $passwort = $cgi->param('param4');
my $ersteller = $cgi->param('param5');
my $kommentar = $cgi->param('param7');
my $id = $cgi->param('param8');

print "In $name sind \& und \# schon verworfen worden";

use CGI;
my $cgi = CGI->new({ foo=> '23 & 42', bar => 42});
my $url = $cgi->query_string;

CGI::a( {-href => "../cgi-bin/skript2.pl?param0=$dsnum[1]&param1=$dsnum[2]&param2=$dsnum[3]&param3=$dsnum[4]&param4=$dsnum[5]&param5=$dsnum[6]&param6=$dsnum[7]&param7=$dsnum[8]&param8=$dsnum[0]"
}, 'aendern');

$ perl -wle'
use CGI;
my $key = "foo";
my $val = "bar&baz";
print CGI::a({-href => "/script?$key=$val&something=else"});'
<a href="/script?foo=bar&amp;baz&amp;something=else" />