Can a child with asperges, who has experienced complex trauma, receive counselling via art therapy?

Not by itself: Art therapy in someone well trained it can be very helpful especially for children - often the express things in art and play which they have difficulty communicating. However much more than that is usually needed with typical asperger's children, let alone those who have severe or complex traumas. Art therapy might be incorporated by a child psychiatrist or psychologist along w range of issues.

See below: This is more an answer from someone who has been in the same boat. There are a lot of treatments that are touted for treating children with autism spectrum disorder. Some seem to work for some children. Some don't. Talk to other parents and see what they have used successfully. If you think it will work, then try it for your child, but do not neglect other trusted treatment options.