You would have to edit the .lnk file to point to the icon you want, and even then it would only work if you're using the shortcut. If you're looking at the .exe itself, the icon will still be the little white box.
You might find the author's email and send him a suggestion for an icon, or even a sample. Icons are hard-coded into the .exe, so only he/she could make the change correctly.
Edit: His email is listed on the page you linked to. I'd give him a buzz if I were you.
