Picking in C2 generally works just like CC. Your problem seems to be you're just missing the "pick by comparison" condition. That's no worry - it's pretty much identical to "For each" followed by "Compare values". For example:
Pick by comparison Sprite.X + Sprite.Y < 100
-> some actions
is essentially the same as
For each Sprite
Compare values: Sprite.X + Sprite.Y < 100
-> some actions
Just a heads up - if you ever can, it's much better to make a blank .capx file showing the problem with as few objects and events as possible. Your project probably makes sense to you, which is fine, but it's very difficult and time consuming to get to grips with an entire problem just to end up looking at one small problem! Thanks.