You can use the .asJSON expression to get a copy of a object's state, then you can use the "load from json" action to load it later.
One way to utilize that is to save it to a global variable on the end of one layout and load it at the start of another. Or another idea would be to make the object global so it wouldn't be destroyed.
If you don't want the warmup at all then you could temporarily add a edit box and set it's text to the particles.asjson once they cover the screen. Next copy that text to your favorite text editor and replace all the " with '. Then put " around the whole thing, it is now a valid text that can be used expressions. So you can make it load that into the object at the start of the layout.