hehe, rainmeter isn't actually a "rain" meter; it is quite similiar to sysmetrix in terms of available functions.
You can modify a rainmeter within Litestep for your own use. You will have to look at the rainmeter setting included with the theme. Rainmeter has its own config file (it's usually kept in the "config" directory,but not always). In that file there are settingslike position on the desktop, and which meters are included with this rainmeter. Hopefully the theme author included a copy of Rainmeters' help file. You can refer to it for direction on what settings control what.
Good luck with it. It is a very cool module indeed!