O.K. so I am playing Vader COTS for the first time. I combine fire with a EVO with a stormie and use Vader CE to reroll. I still get the combine fire right? I was confident going in that a reroll makes it so the original roll never happened so you would, but when it went down the comments from my opponent and the onlookers made me start to think and that is where I get into trouble We proceeded with a ruling of yes you still get the combined, but I would like some extra support since I can't readily find it in the rules or the faq.

Thanks

Yes, you still get the combined fire bonus. It's just like re-rolling an attack with a Force Point.