I have never tryed to open the HWl files located in the M&M directory.It could be one of the following files..
1. HWL = HttpWatch HTTP Watch Log (Simtec Limited)
2. HWL = Corel Shared Writing Tools 9.0 File
3. HWL =Hangman Deluxe Word List
4. Something else lol
You cant open them with mm7view or mm8leveleditor
Anyway here is MM7view