Sub CopySelectedForCompare()
' Paul Beverley - Version 23.10.21
' Copies the selected text to a specified file

myFile = "aaTempFile.docx"

Set mainFile = ActiveDocument
If Selection.Start = Selection.End Then
  Beep
  myResponse = MsgBox("Work with me! Select some text first. :-)", _
  , "CopySelectedForCompare")
  Exit Sub
End If

Selection.Copy

Documents.Open FileName:=myFile
Selection.WholeStory
Selection.Delete
Selection.Paste
mainFile.Activate
Beep
End Sub