How to creat data set with standard SQL link to PLSQL

I need to build a BIP report using RTF as layout

The report has header and detail level

To generate XML with header / detail , I need to write header and detail SQL in the dataset and link both using the primary keys.

However, in the header level query , I need to use PLSQL to get the data.

the problem is if I use PLSQL for the header, it will not generate meta and I cannot link it with detail SQL

I would like to ask how can I resolve the problem ?