Simply replace the unfilled areas such as "[]" and "[date]" with your information.
Dear [name],
Thank you for your comments. A copy of your letter has been forwarded to [name of writer] for [her/his] response. Please note that [name of author] is not able to respond to all inquiries.
Should you have any comments or questions in the future, please do not hesitate to write to this office.
Best regards,