Is there a way to get price data from other sources into Zorro automatically? Or if not, what is the way to manually point Zorro to the new data. I added a dummy line to AsssetsFix.dta in the history folder, which showed up in the Assets dropdown list on the gui so I am guessing it's possible, but I'd like confirmation if that's ok.

You can use the Download sricpt for this. See here:
Manual Export/Import

thankyou.