That's what hensch was saying... read the statutes for other states and see if they have a preclusion for a dismissed and expunged charge for a length of time. He mentioned Maine, so that might be one to look into... and then the others, if that doesn't pan out. The onus is really on you to do the research. Honestly, this is a somewhat obscure point of most laws, and I think you'd be best served by finding one or two you think fit the bill and then ponying up a couple hundred bucks to sit down with an attorney (like hensh, maybe) to get an official opinion on the matter.
Just my $0.02.
Just my $0.02.