Calling a BW Bex Query in Web Dynpro ABAP

Hi Team,

I'm trying to call a BW Bex query in my web dynpro screen. The Web Dynpro is written in our ERP (ECC 6.0) system. I have specific parameters and values in my web dynpro context which I want to pass to a BW query and then display the actual query in my web dynpro. I found an element BIApplicationFrame but don't know if that is the correct way to display the query. Some questions:

1) How do I pass the username/password for the BW system in the Web Dynpro written in ERP?

2) How do I pass the parameters to the query

3) How is the security and roles managed. The web dynpro is enables as an iView in the SAP Portal.

Thanks much for your guidance.

Regards

Sanjay