my @sorted =
    map  { $_->[1] }
    sort { $b->[0] <=> $a->[0] }
    map  { [ (stat)[9], $_ ] } glob('*');

{   # diagnostic
    local $, = ' ';
    print @sorted;
}

my @results = grep { /^$mask/ig } @sorted;
print "Your file is: ", $results[$position-1], $/;

##</code><code>##

my @candidates = grep { /^$mask/ig } glob('*');
my @sorted =
    map  { $_->[1] }
    sort { $b->[0] <=> $a->[0] }
    map  { [ (stat)[9], $_ ] } @candidates;
print "Your file is: ", $sorted[$position-1], $/
  if defined $sorted[$position-1];