pts1, I can already do what you describe

I was just suspecting that something was wrong with what I'm doing because the sustain pedal sustains all the notes of the chord and since I'm a beginner I'm taking things too literally as the others said and wanted to make just the base note of the chord to be sustained and not the others...
ajspiano, now it's clear

yea, that's exactly why I talked about using the sostenuto pedal, I mean, seriously, am I not supposed to follow what's written on the score, or are meticulous people penalized when it comes to music?!
I'm a beginner, studied music language by myself, learnt to play 3 popular songs on piano by myself, and now, 2 months after I first touched a piano, I decided to learn this piece of music which my favorite, a composition by famous rock singer, I can play half the song now with no problems and at the correct speed, I's just that halfway through the song I suddenly stopped, thinking, it sounds good, but is it how it is meant to sound? I actually have a piano version of this song on my computer, and I can hear no difference between my playing and the one one the mp3.
It's a song the means so much to me and I want to play it right, that's why I created this topic, but it remains popular music, not classical, so at the end of the day, I can still play it the way I want, with or without pedaling

Thanks everyone.