How do I program Task Scheduler to randomly cycle through theme?

I know it's possible to make Task Scheduler change themes at certain times, and I've seen various tutorials on it. However, the only thing I've seen has been changing to a specific theme at a specific time. How can I make it randomly choose one, and how do I make it do it every 2 hours or so? The lowest interval I see in there is a one day. And if I can't easily do it this way, is there another program that I can use to do it? Preferably a configurable one so I can tell it to switch Classic Shell XMLs with the theme.

Yeah, that's one of the first things that showed up on Google for me too. It doesn't tell me how to tell it to randomly pick themes or intervals less than a day though.

That's to cycle backgrounds. I want it to do that for THEMES. You know, areo/classic, and the wallpapers and sounds and screensavers that all switch together?

@A Guy
That just shows how to do a certain theme at a certain time of day. I want to be able to do random themes at 2 hour intervals.

I did, but I didn't like your solution, and you admitted you weren't an expert on the subject, so I'm leaving it open. If all else fails, I'll do that though.