Thanks everyone for your replies.
I should add that we're talking about a punk/rock/pop kind of ballad, right? So the chorus is a strong one, with distorted guitars and that part is the one that I'm interested on being as loud as the other songs.
I tried a slightly different approach with EQ and that is helping.
I'll definitively let you know how everything turned out and maybe I'll post some audio examples also, by the way, here's a link to a couple of songs (not the ballad that we're taking about but another 2 songs of the same project, that's the volume that I'm trying to reach):
http://www.gearslutz.com/board/mp3-u...se-listen.html
It's in spanish, sorry if you don't undestand anything. And please tell me what you think, everything is welcomed! Thanks!