The first listed method on the Facebook::Graph::Publish::Post should give this functionality. 
to ( id )
Specify a profile id to post to. Defaults to 'me', 
which is the currently logged in user.

[download]
Then your code would be: 
my $groupid = 12345;
$fb->add_post
    ->id($groupid)
    ->set_message('I like beer.')
    ->publish;

[download]

In reply to Re^2: Post on FB (cron) by Anonymous Monk
in thread Post on FB (cron) by ultranerds

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