How to connect access the data from SQL Server 2008 R2 database using SQL Server 2008 Express through stored procedure?
Firstly, you will need to create a linked server. See this link for more details: http://msdn.microsoft.com/en-us/library/ms188279.aspx
Next, you will need to use a 4 part name. For example:
SELECT * FROM Server.Database.Schema.Table