Set commenter by ID?

[wimg-bstuckey]

I am not sure if i titled this correctly but is there a way when adding a comment to define who is making the comment? I have the accountID of the person the comment is suppose to be made by but not sure how to add it?

        $comment->setBody( $commentBody )
                ->setVisibility( "role", "Users" )
                ->setAccountId( $accountId );