Here are some links that may be helpful in your search for a qualified hamster vet:
The American Animal Hospital Associations
"Hospital Search" allows you to search for "small animal" practices in your area
The Association of Exotic Mammal Veterinarians also has a
Searchable Database for listings by state or country.
Here's a
link to a good article on how to find a small animal veterinarian.
Another note: calling around to veterinary offices which do NOT see hamsters, to see who they refer to, is an excellent idea. They are free to offer referrals based only on the professional reputation of the small animal doctor without fear of competition.