How to Fix Designation - doing accounts works as well as non technical work?

I am working in a construction company. Basically I am Accounts Students, I am doing accounts works as well as non technical work also.
Following activities I am doing in this company:-
1. Tender preparation works.
2. Supporting documents for tender submission.
3. Doing all office works like as, Letters typing, preparing staff attendance sheet and deposit salary in bank.
4. Even some times purchase work also I am doing.
Kindly fix the designation.

You are working as "Document Controller". This designation will be maching to your job profile