Dynamic call to stored procedures

Hi All,
I was looking at the possibility for Report Builder to use data pulled from stored procedures dynamically, that is while the user navigates the report.

I need to implement a report with data pulled from a SQL Server and I’ve been provided with two stored procedures, one pulling master data, and the other for details data.

I have already implemented a DataSource and two Datasets, but I don’t find a way in the tablix to call the data for details dynamically, that is passing as a parameter the master row link.

The details stored procedure accepts among other parameters also the Category of the master, returning details for the subcategories.

Unfortunately I don’t have any control over the stored procedures and they are all I have to query the DB.

Can Report Builder do this or does all the data have to be retrieved before the report is rendered?