Hi Anuradha,
Code level customization of Infoview, BI Launchpad, CMC and other web applications in BusinessObjects Enterprise is not supported and not recommended.
You can refer to the following SAP Note for the support policy on customization:
The Note has a link to SAP BusinessObjects BI Customization Guide.
You can refer to the customization guide for all the allowed customizations.
Regards,
Renu