I've tried setting the constant combinator to -1 copper ore, and then the circuit condition on the belts to hold, disable/enable, and circuit condition "red star" < 1-- this was explained in another forum post viewtopic.php?t=54547.
I think I'm messing up because of the number I'm choosing. Anyway, I've fiddled with it for a while now, and I was wondering if someone can help. Cheers!