Anna,
Thanks for the answer and the link, but it's really outside the very narrow scope of my intended question. I hate to be a stickler on this, but I'm really looking for that one "bulls-eye" answer.
As I stated in a comment previously, whether or not I use task scheduler is not an issue. Finding a way to allow a power user or a regular user to run the built-in defrag utility as designed (with the emphasis on "as designed") at his or her discretion was the basis of the question. Also, and again, as mentioned above, a registry hack or something similar is what I'm looking for. I know about the alternatives, but that wasn't the specific question. I hate rejecting answers, but I'm really looking for only that one very specific thing. I suppose, however, what I'm looking for doesn't exist.
In all the questions I've posted, I think I've accepted close to 95% of the answers, and awarded close to 200,000 points. I really do hate rejecting them, and in a way, I wish I didn't post this question. I know that the professionals who regularly answer questions look for ways around a problem if there's no apparent "direct" solution to it. That's what I do, and sometimes that's all a person can do. And that's what's happening here.
And since I have the opportunity, I'd also like to let you know that I admire your tenacity, considering all that's transpired in recent months about various things. You've contributed a great deal to this forum, and I'm glad you found it fitting to post an answer to my question.
Best regards,
Maxwell