advice on application for secondary special school

[coyneyc]

Dear All
I have not blogged or visited this site since I lost my daughter Grace 13 years ago - I have since been blessed with two more children. One of whom has autism and attend a special needs primary. He is now ready to apply for secondary and we are advised that we need to write a strong application as the paces in the school we want number just 22 for the whole year group.
Mainstream or IR is simply not an option for him, any peer group or the teachers. Could anyone give us any top tips about how to format the letter and things to include?
I hope life is treating you kindly.