How can I synchronize data between MS Access and SQL Server databases?
Basically, you want to create a distributed query. This is a very common, and relatively simple process from a SQL Server standpoint. From the SQL Server side you can add a linked server then access the external data by using OPENDATASOURCE.
Here’s a good start-to-finish walkthrough entitled Configuring a Linked Microsoft Access Server on SQL 2005 Server that should help in your particular case.