The only way to do that, of the places I'm aware of, is to get them to change your starting level from "fresh grad" to "engineer with 2 years of experience".
Since the people involved in setting salary are not involved in setting level, that mostly doesn't happen, because they're not going to countermand the leveling decision just to get your compensation up.
When did you do this? In the current hiring climate, I can't really imagine that happening.
I tried this with one, and they offered me a larger signing bonus.
What I didn't realize was that they just ended up deducting that from my year end bonus.