I figured it out myself, and in order to help others avoid the frustration I have gone through, I'll show how I did it.
Step one: Create a new page. It's that easy. Just make the page, title it whatever you want. I'll be calling mine example.
Step two: Find that in the code. If you hold down ctrl and then press f once you're looking at the code, you'll be able to search for the name you titled the page. It should look like this:
Step three: Add the lines of code that give the object, the page you created, an alt list.
This is the code:
<alt type="stringlist">
<value>example1</value>
<value>example2</value>
<value>example3</value>
</alt>
Change the values (example1, example2, and example3) to whatever you want. Then copy and paste this code after the <description type="string"></description> line but before the </object> line.
It should look like this:
That's it. Now to test it, just add the line {rndalt:example} (except with whatever name you chose for your object/page) in the text processor or wherever you want.
I'm sure the more tech suave are laughing at my expense, because it is probably something really basic. But I don't know anything about code and I figured it all out myself, so I'm hoping this'll help anyone struggling like I was.