The Calgary area has lots of great private and independent schools that cater to kids with Special Needs. Rundle College has a specialized program for students coded with learning disabilities and 4 locations. The Academy is located in the SW. Green Learning Academy offers an alternative to traditional education. Webber Academy is not a special needs school but may accept some students. It is located in the in the SW.
A full list of schools and a useful compare tool is available on the Calgary Private School page.
The Alberta Board of Education has more information on private schools in the Calgary area at www.education.alberta.ca
Good luck with your search!