create table t as
  select rownum x from dual connect by level <= 1000;
  
create table t_export (
  x int
);

create table log_count (
  row_count int
);
  
declare
  rws pls_integer;
begin
  insert into t_export
    select x from t
    where  x <= 100;
    
  rws := sql%rowcount;
  
  insert into log_count values ( rws ); 
end;
/

select count(*) from t_export;

COUNT(*)  
100     

select * from log_count;

ROW_COUNT  
100