First off the AuJus part is basically free..it is just a beef broth.
The meat depending on the leanness of the cut could be 1-2 points per ounce of meat.
The bread (also dependent upon the heaviness of it) could be about 2 points per ounce.
Cheese is 3 points per ounce for full fat.
You can try
www.calorieking.com or
www.dietfacts.com to see if you can find a beef aj jus sandwich and get a close guestimate. Or you can use those sites to build your sandwich.
At
www.dlwz.com (under her restaurants) I found:
Boston Cheesesteak w/fries & Au Jus (1790 cal/87 g fat/172 g carbs) 44
and the Fries there are Fries (700 cal/33 g fat/87 g carbs) 17
So that sandwich alone is about 27 points.