Selected Answer
You can use the CONCATENATE function for this, in fact concatenating 3 parts of your desired output: leader, date and trailer. All three can be of any length or format. I omittrd extra text which you may like to add as desired.
=CONCATENATE("Under instructions .. on ",TEXT($B$1, "dd mmmm yyyy.")," Upon thorough ""Damage Report"".")
Below is a variation of the above. The function name is omitted and the function's commas replaced with ampersands. Many programmers prefer this version because it's shorter.
="Under instructions .. on "&TEXT($B$1,"dd mmmm yyyy.")&" Upon thorough ""Damage Report""."
Observe how th date format is set according to your preference and to to add the quotation marks around "Damage Report".