PARAMETERS DATE_CUR DateTime,
           OF_CAT_ID Long;


SELECT offers.offer_id,
       offers.offer_number,
       offer_cats.offer_cat_name,
       clients.client_name,
       Nz([sum_on_date],0) AS p_sum_on_date,
       Nz([sum_payed_on_date],0) AS p_sum_payed_on_date,
       Nz([sum_payed_on_date],0)-Nz([sum_on_date],0) AS saldo,
       Sum(peni.peni_sum) AS [Sum-peni_sum]
FROM (offer_cats
      INNER JOIN (clients
                  INNER JOIN ((offers
                               LEFT JOIN qrySaldoPayed ON offers.offer_id = qrySaldoPayed.offer_id)
                              LEFT JOIN qrySaldoPlanPayment2 ON offers.offer_id = qrySaldoPlanPayment2.offer_id) ON clients.client_id = offers.client_id) ON offer_cats.offer_cat_id = offers.offer_cat_id)
*вот этот*RIGHT JOIN peni ON offers.offer_id = peni.offer_id
WHERE (((offers.offer_cat_id)=[OF_CAT_ID]))
  OR ((([OF_CAT_ID])=0))
GROUP BY offers.offer_id,
         offers.offer_number,
         offer_cats.offer_cat_name,
         clients.client_name,
         Nz([sum_on_date],0),
         Nz([sum_payed_on_date],0),
         Nz([sum_payed_on_date],0)-Nz([sum_on_date],0);