It sounds like you're trying to have all accounts point to a single folder instead of using CRM's functionality to create new folders for every account.
Create (either programaticaly or manually) new "Document Location" records for every account and point them to the same sharepoint folder (rather than having sharepoint auto-create the new, unique locations.)
Scott Sewell, CustomerEffective | http:\\blog.CustomerEffective.com | Twitter:@ScottSewell