Letter Format Need - Fuel Reimbursement For Employees

Hi all,
I'm working as an HR Executive at a Private company. We are planning to give a new benefit for some managers as follows;
1. Fuel reimbursement up to $100 per month
2. Mobile Phone bill reimbursement upto $5 per month.
I need your help to create a letter for this (considered as an Increment). Please help.
Regards,
Irosh

Anyone can help?
I need a sample of Fuel Reimbursement Policy/Procedure or a Letter.
* They have a limit upto $100 per month
* They need to provide bills by end of the month