It is not possible to use the ExNorms tables to arrive at extended scores if you do not have raw scores for the relevant subtests. The sum of scaled scores used for each composite is derived from the extended scaled scores. If you used the original scaled scores, you would end up with the same non-extended composites as you had originally on the standard norms.
It may be worth pursuing an addendum if your child
a) has more than one scaled score of 19 (or possibly 18, if it is an older child)
b) was a preteen at the time of testing (with some older exceptions).
In a few cases with more extreme extended scale scores, the ExNorms will make a difference for an older child, closer to the age-limits of the test (the norms end just before the 17th birthday). I have had one adolescent where the Extended Norms resulted in a modest, but significant, increase in one composite.
