excellent suggestions etc but the tricky bit of the question is how to call this perl script from command line to request this particular HoA (names) or another, e.g. birthdates.
without coding this myself, I suggest that part of the solution would be to use one of the standard args modules, which provides a nice mechanism to supply and parse zero or more args to perl in any order/combination. anyway, something possibly to consider. the harder bit of not passing symbolic reference can be done by testing the value supplied to the perl script against possible requests in a switch e.g.

my $request = shift;
switch($request) {
  case 'names'  print @names;
  case 'birthdays' print @birthdays;
  else print 'unknown request`;
}
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and so forth. if as in my example the names and birthdays are parts of a proper record set and related, e.g. person 1 -> birthday 1, then a slightly more elaborate structure can be created with a hash etc.
in any case, using such switch or even if statements obviates need to use directly the value of one variable as a symbolic link to another variable.