my $HoA;
$HoA->{CountArray} = [1, 2, 3, 4];
my @AlphaArray = ('a', 'b', 'c', 'd');
$HoA->{AlphaArray} = \@AlphaArray;

DoStuff($HoA, 'AlphaArray');
sub DoStuff
{
  my $HoA = shift;
  my $desiredArrayName = shift;

  die "There is no such thing as '$desiredArrayName'" unless exists ($HoA->{$desiredArrayName});

  foreach my $value (@{$HoA->{$desiredArrayName}})
  {
    print "$value\n";
  }
}