$ cat t.pl
#!/usr/bin/perl

# Prevent symbolic references, etc. in general
use strict;
use warnings;

# Use our instead of my to ensure that the value is accessible
our $boom = 'Kaboom!';
our $bam = 'Kerblam!';                                                          
 
# Unfortunately, the call looks odd...
say_var('boom');
say_var('bam');

sub say_var {
    # Turn off strict for now   
    no strict;
    my $t = shift;
    print "\$$t = >$$t<\n";
}   

$ perl t.pl
$boom = >Kaboom!<
$bam = >Kerblam!<