BEM, welcome to the forum!
You might be able to get some tips and ideas from other parents with special needs children here:
http://forum.brillkids.com/parents-with-special-needs-children/I am not an expect, but I would say that LR can definitely help with vocabulary building, and reading instructions, and the good thing you can repeat each lesson several times and every time your child would see words written in different color, different font and size, illustrated with different picture and video and pronounced by a different person, -- the algorithm that works well for special needs children, as it is repetition combined with variety at the same time. Just a thought! I am looking forward to responses from the parents that use LR with their older children with special needs!
You also can print out flash cards straight from LR lesson and use them for various games!