How to customize SAP REPORT in ENTERPRISE PORTAL

Hi,

I created some SAP Report (Transaction iView) in portal. At present in preview it shows all fields and column which is available in R/3. But I need to customize the field and column of the SAP report, depends on the user .I want to provide only certain field and column only. How to achieve my requirement? It is possible to do the customization by EP?

Thanks,

Kundan