The Irish striker saw his opener at Loftus Road levelled by a stoppage time Kieron Dyer strike but believes his team can progress in the replay - and then go on a deep run.
Long explained: "The gaffer said before the game: "All you have to do is win six games and you win the FA Cup".'
He added: "It's a great chance to win a medal and, at the end of your career, you want something to look back on. We've got a great squad of players here and we can beat any team on our day so this is a great chance for us this season.
"QPR will have to travel now and they are in a bit of a dog-fight at the bottom of the table so that extra game won't do them any good."