I want to have something like this: "keep 1000 eggs in storage, dump the rest into IC2 recycler".

Currently configuring an exporter to export eggs doesn't allow keeping a certain amount stashed, and the simplest existing way of achieving this I can think of - write a program for OpenComputers to remove excess items from the network completely and process them separately.

You can do this using Detector .

1. Place the Detector. Configure it to "Emit redstone signal when above the amount".
   
   1.2 Specify the amount of block/items and the block/item itself.
   
2. Place the Exporter and configure it to export only with redstone signal.
   
3. Profit.
   

Oh, thanks, that's indeed simpler than using OpenComputers :) One problem though: redstone signal doesn't differentiate between items, so separate detectors and exporters are needed for every item type.

I think this is fine as is.