jader
Here is another possibility, or possibilities.
Many years ago (2004 - 2005) Darrell May created an rpm
e-smith-service-control-1.1.0-06.noarch.rpm
Maybe you could tweak that to do what you want, and then make it accessible via the user manager contrib.
If you cannot find it by searching, I have the old rpm & src rpm.
I also wonder whether the sme7admin contrib, now sme8admin contrib would do what you want or could be made to do what you want.
Also many years ago, Dungog had a contrib that added an icon to the Windows desktop to start (and stop) the dial up modem service, I forget the exact details, but it was before the days of broadband, so you might want to ask Stephen at dungog.net for help re "how to do it".