Simply replace the unfilled areas such as "[]" and "[date]" with your information.
Dear [name],
We have a new employee in our office! You may have noticed [him/her]. Go up and introduce yourself to [new employees name], who is a [new employee title] working with us to [new employee job function].
I'm confident that [new employees name] will be a valuable addition to [name of company], bringing many skills and talents to better our operation.
Sincerely,