Are you going to use the convection only? If so, I got a recipe online which I posted in another thread about cooking turkey in microwave. I have used it at least three times and it comes out great. It was 375 degrees, but only cooking for about 2 and 1/2 hours for a 12 lb turkey, IIRC.
I looked for it and you can find the link on this board if you go to the Cooking Forums and click on Cooking Accessories and then click on Appliances and look for the thread called Microwave and Convection Oven. I posted the link in that thread to a complete explanation on Convection cooking a Turkey with recipes.