help need it

hi everyone,

i've got an oracle query that is something like this:

select id_mensagem, ds_description, e_mail, to_char(ds_date,'DD/MM/YY -
HH24:MI'), assunto,
respondidas, mensagem, mensagens.id_resposta
from
(select id_mensagem, ds_description, e_mail, ds_date, assunto,
mensagem, id_resposta,
RANK() OVER ( ORDER BY id_mensagem desc )as i
from varForum
where varForum.id_resposta varIdComparator) mensagens,
(select id_resposta, count(id_mensagem) respondidas
from varForum
group by id_resposta) respostas
where mensagens.id_mensagem = respostas.id_resposta(+)
varRange
order by ds_date desc

now i need to pass the query to postgresql, does any one can help me.

best regards,

etur