You can configure new data sources using scripting and the wsadmin tool.
In WebSphere Application Server, any JDBC driver properties that are required by your database vendor must be set as data source properties. Consult the article Data source minimum required settings, by vendor to see a list of these properties and setting options, ordered by JDBC provider type. Consult your database vendor documentation to learn about available optional data source properties. Script them as custom properties after you create the data source. In the Related links section of this article, click the "Configuring new data source custom properties using scripting" link for more information.