How To Add Columns And Use Them At Run Time Using VB 2005

In order to allow my customers to use their existing data and install updated application, I want to be able to add columns to existing CE tables at startup time, and allow the user to enter data into the new column(s) immediately. I used the ALTER TABLE command as shown in the example below:

cmd.CommandText = "ALTER TABLE tblStores ADD dtDemoDate datetime, dtDemoMode int"

cmdexe = cmd.ExecuteNonQuery()
To add the column, But this does not set the columns in the attached dataset. The program sees the columns and data is able to be added, but is not then in the underlying table? What else do I need to do?

Thank you - b2bMan