Formal letter seeking differnt peoples approval

Hi there,

I need to write a formal letter to the Dean of faculty for approval. Meanwhile, i also need my supervisor to sign his approval somewhere on the same piece of letter. He told me to write as:

Prof. ***
Dean
School

Through: Dr. ***
Academic supervisor (he will sign here)

Dear prof. ***

blahblah

yours sincerely

Can someone help me to clarify whether this is the way to write for approvals from different parties. Thank you in advance.