I needed the same, so using the Helpfy Answer I created this.
I work for me, since I'm using really big data, and we had some memory issues. Now it's fine.
let _step = 3;
let _cont = 0;
let _rows = 30;
let _carq = 0;
let _header = 0;
for _cont=0 to $(_rows) step $(_step)
let _header = $(_step)*$(_carq);
let _carq = $(_carq) + 1;
LOAD @1 as Cod,
@2 as Desc
TesteNrLinhas.txt (txt, codepage is 1252, no labels, delimiter is '\t', msq, Header is $(_header) lines)
RowNo() < $(_step)
Store TabX into TabX$(_carq).txt (txt);
drop table TabX;