How can I write an RRDI report showing work items associated to a build?

I am helping my client migrate their RTC reports off of BIRT and onto RRDI.  So far, this effort has been going well.  The performance of RRDI reports is significantly better than BIRT, and having the ability to schedule reports and display the resulting views in RTC is huge.  However, the issue I described above is preventing my client from doing a full migration from BIRT to RRDI.  Since RRDI is being positioned as the strategic custom reporting platform for CLM, it would be nice if RRDI could have full access to the data in the data warehouse (like BIRT has).