I would start with your pediatrician. You want to be sure that you choose an audiologist that specializes in CAPD - most do not. In my area, the major children's hospital offers full CAPD evaluations (not screens).
You might also want to check out his language processing. CAPD, dysgraphia and poor spelling are usually related to language processing skills. And again, you want to be sure you get a very experienced speech and language pathologist that specializes in children and understands how receptive and expressive language relate to our educational system, attention issues, CAPD and LD.
Organizations such as the International Dyslexia Association may maintain lists of evaluators.
