Custom signature position on uploaded file

Question

Hi guys,

I have a problem on solving a requirement, which is:

   1. Upload a file (doc, pdf)

   2. Read and view ONLY a selected page on uploaded file (normally LAST or FIRST page)

   3. Find  a position on the selected page for the signature position

   4. Save the position on the database or a variable.
I have been stuck on this problem for weeks, I really appreciate if there is any solution you can think of.
Thank you so much!