adan.ribeiro's post in Format in Brazillian Currency (Real - R$) style was marked as the answer
Well, I solved my own issue using MySQL statement instead of properties from iReport. My solution was an adaptation from this site (Pt-BR):
http://paposql.blogspot.com.br/2011/12/funcao-para-formatar-moeda-em-reais-no.html
Then I just replaced the value in the sentence by field "valor_aquisicao" like this:
SELECT CONCAT('R$ ',REPLACE(REPLACE(REPLACE(FORMAT(valor_aquisicao, 2), '.', '|'), ',', '.'), '|', ',')) AS 'Valor' FROM [...rest of statement...]
It suited very well and fixed my problem. as you can see in this image below.
