formal letter

Dear mam,
i want to write a formal letter,so can you please help me out on that.
The letter is regarding dat ''a social club is trying to help some under preveledged children,and requesting a biscuit company to provide them packets of biscuits for atleast one year.''
so i wanted to know how to write that in a formal way.
thanking you,
anurag banerjee

[Anglika]

Is this an exercise?