If you call the bank, their REO department may not handle the sale. If the bank(investor) has a mortgage servicer that handled the foreclosure, then you would have to go through a different company. It may be easier to get a buyer's agent as Xsatyr suggested.
So if the house has been sitting there vacant for a year or so, I assume that means no electricity and water which means no AC. Isn't that a big problem, won't there be mold/mildew problems etc? That something I've always wondered about foreclosures