If values are non-repeated, as it appears in %order, you could also use a reversed version of the hash to do the sort. Please note that this doesn't hold if there are repeated values in %order!

In that less general hypothesis, you could do:

my @ordered ;
my %r_order = reverse %order ;
# %r_order is now ( 1 => 'DATE', 2=> 'CPP'...
# ...and so on.

{
  # slice %order in @temp
  # (the following two lines could be compacted into one
  # but... KISS :-)
  my @temp = sort { $a <=> $b } @order{@to_be_ordered} ;
  @ordered = @r_order{@temp} ;  

  # @temp will now disappear :-)
}

# Now @ordered contains the sorted list based on
# @to_be_ordered, so...
&do_what_you_want_with(@ordered) ;
[download]

That should work.

Ciao!
--bronto