Integrating Zen Cart with Live Datafeed

I would like to integrate Zen Cart with my suppliers live datafeed. I would like their active/inactive parameters to translate to my stock parameter, so that ..

if they show item active = my product is in stock (stock lvl is 100)
if they show item inactive = my product is out of stock (stock lvl is 0)

they offer a .dat tab separated feed, or an .xls feed.

My model numbers equal their model numbers.:huh:

I'd like my products stock levels to be updated every half hour or so.

I looked at EasyPopulate and installed it, but I don't think it's really what I want. My supplier suggested a cron job to do this - can one be set up to make these changes?

Thanks for any helpful hints!