میتونه اینطور شروع بشه:

Certificate

To whom it may concern;

This is to certify that Mr. ………………, son of …………, holder of ID Card No. …………, issued in ……………., has been working at this company as a "job title" strong in "your specialization" from June. 22, 1998 until June. 22, 2003 on a part-time basis (30 Hours per week) and from June 22, 2003 until now on a fulltime basis with monthly salary of "amount" Rials with a great professional information and behavioral specifications as : self motivated , responsible , good loyalty , well coordinator and good communication skills.

و بعد اینطور ادامه پیدا کنه (مثال برا رشته کامپیوتر):

His main expertise is implementation of applications in C# language.

The aforementioned is specialized in the following fields:

C# programming windows base applications

The aforementioned has performed the task of C# Programming and Software Engineering in the following projects:

- As a Software Programmer , Software Analyst and software developer :
Web-based application for ""Client Name"", Research Affairs Organization including 9 subsystems (32 months)
written in C# , SQL server 2000 Database

Yours faithfully
Company Name
Managing Director

Address,
Phone,
website