I used to have an ibanez prestige S with piezo outs. Matrix is right that its never gonna be 100% but I got what I thought were good results.
I eq'd the shit out of it, removed a ton of core mids, controlled the low end and put a colorfull boost up top with waves Veq, sort of a controlled smiley face eq curve with all the junk at the extreme high and low removed. Then I added a touch of compression with an La2 style comp, I forget which one I used, maybe the antress modern one. Then once I got it sounding pretty great I thought it was a bit upfront so I added waves true verb to it and put it on the guitar room setting, blended in early reflections until it smeared enough of the signal that it sat in the mix pretty well and wasnt so obviously a direct sound. Good Luck.