Three tier architecture best practice approach

� 

Hi,

� 

I have one small application (AddIn for Excel 2003 with VS 2008 C#). I would to apply the three tier model.

The problem is that I donâ��t know wich are the best candidates for� entities for the business level.

My application read the connection string from one XML file. Then, read the table names from the db SQL 2005 choosen by ...