The key is to extract the numeric part of each filename, and compare numerically those values.
Something like this will do the job:

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

However, that is not optimal for the sort.
You can resort (heh) to a Schwartzian Transform to improve efficiency:

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

jdporter
The 6th Rule of Perl Club is -- There is no Rule #6.