my $prim_to_test = ${ num_to_nat(2) }[0]; #get_wildmarks(); 'aa'

my $split_pattern =  qr/(\Q$prim_to_test\E)/;

print "split_pat: $split_pattern\n";

my @splitted = map
"$_ x $1", ( $wildmarks =~ s/(?=$split_pattern)$split_pattern//g );

print "splitted: ", join " \N{U+68} ", @splitted, "r: $wildmarks";

output:splitted: 4 x aa h r: a