SELECT KOD,SUM(SUMA*( 1 - 2 *OP)) AS OST,MAX(DATA) AS P_DAT FROM TDV WHERE DATA < NADAT GROUP BY KOD ;
 HAVING SUM(SUMA*( 1 - 2 *OP)) #  0  ORDER BY  2  INTO CURSOR CDEB

*Пусть код контрагента kod_a ,тогда для формирования этой таблицы используем SQL-запрос:

select data,n_dok,suma*( 1 -op) as sum_p,suma*op as sum_r,suma* 0  as ost_tek from TDV ;
WHERE KOD=KOD_A AND DATA <NADAT  ORDER BY DATA,OP INTO tablе AKT

*Для вычисления поля OST_TEK:
m.ost= 0 
sele akt
SCAN
	M.OST=M.OST+SUM_P-SUM_R
	REPLACE OST_TEK WITH M.OST
ENDSCAN

select ;
	TDV.data, ;
	TDV.n_dok, ;
	TDV.suma*( 1 -TDV.op) as sum_p, ;
	TDV.suma*TDV.op as sum_r, ;
	SUM(TDV2.suma) as ost_tek ;
from TDV ;
inner join TDV as TDV2 ON TDV.KOD = TDV2.KOD and TDV.data >= TDV2.data ;
where TDV.KOD = m.KOD_A and TDV.data < m.NADAT
group by ;
	 1 , 2 , 3 , 4 

select ;
	TDV.data, ;
	TDV.n_dok, ;
	TDV.suma*( 1 -TDV.op) as sum_p, ;
	TDV.suma*TDV.op as sum_r, ;
	SUM(TDV2.suma*( 1 - 2 *TDV2.op)) as ost_tek ;
from TDV ;
inner join TDV as TDV2 ON TDV.KOD = TDV2.KOD and TDV.data >= TDV2.data ;
where TDV.KOD = m.KOD_A and TDV.data < m.NADAT
group by ;
	 1 , 2 , 3 , 4 

SELECT Tdv.*  FROM rsp!tdv;
 WHERE Tdv.data <= NADAT AND Tbdv.KOD = m.KOD_A order by Tdv.data, Tdv.op, Tdv.n_dok, Tdv.scet into cursor CORD

SELECT RECNO() AS NZ,CORD.*  FROM CORD ORDER BY  1  INTO CURSOR CDV 

USE IN CORD

SELECT CDV.data, CDV.n_dok, CDV.sklad, CDV.scet, CDV.dog,;
  CDV.suma*( 1 -CDV.op) AS SUM_P, CDV.suma* CDV.op AS SUM_R, ;
 SUM(CDV2.suma*( 1 - 2 *CDV2.op)) AS OST, CDV.op;
from CDV,CDV as CDV2 WHERE CDV.NZ >= CDV2.NZ ;
group by CDV.NZ INTO CURSOR CAKT