Confirmation letter lost by trainee - issuing a revised letter - earlier given confirmation letter is now invalid?

Dear All, In a company, if a management trainee has lost his confirmation letter, we are issuing him revise letter, can you please suggest me few lines to indicate that the earlier given confirmation letter is now invalid?

Hi Rammy,
You can start your letter as follows -
"In supersession of our dt.------(mention the ref. of previous letter), we hereby state that Mr...............
or
Just retype the contents of the same(previous) letter as it is, without changing anything, sign it and affix a rubber stamp mentioning "DUPLICATE" at the top of this letter.
or
Retype the contents of previous letter and change the date & reissue with current date.
You may decide on any of the above or other options.