Private Sub CommentFileSample()
    Const strFn = "CommentFileSample"

    Dim strInFile As String
    strInFile = CombinePathAndFile(GetWindowsDirectory, "WIN.INI")
    strInFile = InputBox("Input file: ({Esc} cancels.)", strFn, strInFile)
    If Len(strInFile) = 0 Then Exit Sub

    Dim strOutFile As String
    strOutFile = GetTempFileName(Null, strFn)
    strOutFile = InputBox("Output file: (FILE WILL BE OVERWRITTEN; {Esc} cancels.)", strFn, strOutFile)
    If Len(strOutFile) = 0 Then Exit Sub

    Dim strPrefix As String
    strPrefix = InputBox("Prefix file lines with: ({Esc} means no prefix.)", strFn, "/* ")

    Dim strSuffix As String
    strSuffix = InputBox("Suffix file lines with: ({Esc} means no suffix.)", strFn, " */")

    MsgBox "Return = " & CommentFile(strInFile, strOutFile, strPrefix, strSuffix) & " (True means success; False means failure.)", vbInformation, strFn
End Sub