foreach my $file ( sort {
    my($as,$an) = $a =~ /^(\D*)(\d+)/;
    my($bs,$bn) = $b =~ /^(\D*)(\d+)/;
    $as cmp $bs or $an <=> $bn
  } keys %hash )

##</code><code>##

  foreach my $file (
    map { $_->[0] }
    sort { $a->[1] cmp $b->[1] or $a->[2] <=> $b->[2] }
    map { [ $_, /^(\D*)(\d+)/ ] }
    keys %hash )