It's doable, but you'll need to make sure you copy the outline of your pants onto paper, not fabric. Using pen, you'll need to mark off where every seam is and the outline of all darts too by following the stitching of the ripped out seams. Then use the copy as your pattern.
I assume you've already googled for the manufacturer of the pants to see where you could buy another pair, yes?
An even better way is to go to your friendly dry cleaner/tailor and see if they can't make you a new pair.
