Report Service And Report Builder Issue

SQL SERVE 2012

In our web site project we use ReportingService2010 Methods to show and operate folder and report which stored in Report Service, in our project configuration file, we use windows authentication mode for Report Service.

In requirement

1. User can show and operate folder “A” and folder “B” (we can create and delete report or folder) in web site.
2. User can’t use “Report Builder” to save reports which created by Report Builder to folder “B”, Reports which created by Report Builder only can be saved in folder “A”.

[User click “Report Builder” button in our web page to start Report Builder, use  “Report Builder” to create report, if user want to save report, we need to hidden folder “B” in “Report Builder” or we need to remove some operate right from folder “B”.]

We have no solution for this requirement, could you help us?