Thanks moritz, in the mean time i figured out this:

my @dnsSuffixList = qw ( 10.0.0.1 10.0.02 10.0.03 10.0.04 );

my $str = join ('#;#string#', @dnsSuffixList);
$str =~ s/$str/#{#string#$str#}#/;
# print $str;
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What do you think is faster? sprintf or sed?