(html, codepage is 1252, embedded labels, table is @1);
if(peek(Accountnum)=Accountnum and peek([Año_Acum])=[Año_Acum],peek(Acum_Importe)+Importe,Importe) as Acum_Importe
resident INPUT order by Accountnum, [Año_Acum] asc, [Mes_Acum] asc;
drop table INPUT;
As I understood your request, I start the accumulation for each account and per year. If you don't want to reset the accumulation on a year change, just remove the "and peek([Año_Acum])=[Año_Acum]" from above if statement.
The answer has a problem becose in my input table i don't have the Acum_Importe Field from this paort of load expression "peek(Acum_Importe)+Importe" or the correct load expression is "peek(Importe)+Importe"?