my $query = ":$name:$vorname:$plz:$tel:$tel49:";

##</code><code>##

my %query_for = (
    0 => "::",
    1 => "name IS \$name",
    2 => "vorname IS \$name",
    ...
);

##</code><code>##

my %query_constuctor_for = (
  ...
  18 => sub { return ":NIL/$vorname::$tel49:" },
  19 => sub { return ":$name/$vorname::$tel49:" },
  ...
);

##</code><code>##

my $query_maker = $query_constructor_for{$bitvector};
defined $query_maker or die "Combination invalid";
$query = $query_maker->()