# Bozo.pm
package Bozo;

use Exporter;
@Bozo::EXPORT = 'go_bozo';

sub go_bozo { return "bozo!" }

1;

##</code><code>##

# Foo.pm
package Foo;

use Bozo;

sub proxy { return go_bozo() }

1;

##</code><code>##

# prog.pl
use strict;
use warnings;

use Bozo;
use Foo;

print go_bozo();
print Foo::proxy();  # or Foo->proxy() if you want 'Foo' sent as the first arg...