I'm just wondering what your actual "strings" are. If they're strings of alphanumeric characters of fixed or finite length, of course that's the kind of thing that Perl can do very well.

Something like

$inverse_regex = 'a.b';
for (0..9,a..z){
($result = $inverse_regex) =~ s/\./$_/;
print $result;
}
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would be simple.
--

($_='jjjuuusssttt annootthheer
     pppeeerrrlll haaaccckkeer')=~y/a-z//s;print;
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