The term won't be there if it's part of the sentence that you want to append so no point in looking for it?
Make a string variable (strResponse ? ) = the entire contents of the field; e.g. strResponse = Me.txtMyControlName.
Then write
strResponse = strResponse & vbCrLf & Date & ": Complaint closed. This has been addressed with the customer."
That assumes you want a line wrap for the ending. If not, remove the vbCrLf
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.