What to do???

If you have read my blog before you know my oldest son Noah, is autistic. We are having major issues at school and I am getting very frustrated. No, he is not disruptive or a trouble maker when he is there(like he is at home lol). I adore his teacher on a personal level, so this isnt a slight on her, but Noah is learning NOTHING! Today he seems to have sat in a chair for the ENTIRE day doing nothing at all because he refused to work. They did feed him, of course, but he was not allowed to eat with his classmates. He KNOWS he should work but has little or no concern for the consequences if he doesnt. He is below a preschool level and will be 8 in two weeks. I have tried rewards for good days, punishments for bad (no tv, toys, going places ect.) I have tried begging and yelling but it doesnt matter, he truly doesnt...ugh I dont want to say he doesnt care... its more that he doesnt understand why it matters if he can write the letter B. I have been brain-storming with my friend Erin on NEW ways to get him to WANT to learn, so when I go to his IEP meeting I bring something to the table. Anyone have ideas???