Here's a thought - why not put those semi-constant values in some external module that inherits from Exporter. You can then write a number of "accessor" functions to those values, and import those into your script. Something along the lines of:

use 5.6.0;
use strict;

package MyConstants;

use Exporter;
our @ISA = qw(Exporter};

our @EXPORT_OK = qw(Foo Bar);

my $foo = 5;
sub Foo { $_[0] ? $foo = $_[0] : $foo }

my $bar = 3;
sub Bar { $_[0] ? $bar = $_[0] : $bar }

1;

__END__
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Thus, you can get and set these values. This, in case you're wondering, if a very rudimentary datastructure object.

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