Service tax registration via post or representaion

Hi

I have applied service tax via online, i am required to submit the application along with supportive doc to  respectivitive jurisdictional Range Officer, but i have travlled out of india and can not submit the doc my self, kindly help me in understanding if its possible that someone can submit the docs on my behalf, if yes what additional doc do i reqiure to submit aside to authorization  letter

Thanks in advance for helping out