hey..
There do make these feeder containers for crix, They are a little plastic box with a lid, and a door on the lid so you can put your crickets inside the container. Then they have a long tube that sits at an angle half inside the plactic box, and half outside the box. So when you need some feeders your just pull out that skinny tube and shake them into the bag that you have your calcium in. I've never used one personally, so I'm not sure if they work really well, but we sell them at the pet store I work at. You could also put a piece of egg carton, or maybe a cardboard tube from a roll of TP, and shake them from the cardboard into your bag.
I donno..I just catch mine, lol. I'm pretty used to I guess from hand counting out hundreds at a time sometimes at work..haha
Good Luck!
-manda
Heres a link to something like what I'm explaining.
Kritter Keepers & Cricket Containers