Exporter使え、とゆーのがあったと思うのだが。
[Hoge.pm]
package Hoge;
use base qw(Exporter);
our @EXPORT = qw(HOGE HIGE HAGE);
use constant HOGE => "a";
use constant HIGE => "b";
use constant HAGE => "c";
1;
---
use Hoge;
print HOGE, HIGE, HAGE, "\n";