ok, heres the best way, sorry if you already know some of this.
the left and right locators are your most important tools for focusing on bars / loops and sections of your song.
make a new midi track and assign it to your instrument / device etc.
you need to drag the left and right locators around lets say... a 1 bar loop. when you got your left /right locators in place double click in between them to create a part.
double click on the part to view the part in key edit mode (ctrl+E) then start clicking in your four kick drums.
once your kick drums are in, close the part. Then use the repeat function (CTRL+K), type in 31 into the amount box, hit ok and there ya go!
When repeating I tend to use ghost copies, dunno why just habbit i picked up whilst using cubase on the atari ST for years when huge amounts of memory was unheard of.
I hope you understood that, if not then i will re-explain with screenshots of each process.
fluxtah