for (my $candidate = 10234; $candidate <= 98765; ++$candidate) {
    # we want to jump eg from 10992 to 11000
    # note not 'next': we've already incremented if the s/// succeeds
    redo if $candidate =~ s{ ^ (.*? (.) .*? \2) (.*) }{
      ($1 + 1) . ("0" x length($3))
    }ex;
    ...
  }