Recommendation on building a universal report

I need to create a report that will be used primarily as an offline data extraction tool (to free up users’ computers from being busy while these extracts are done via SmartView). I’m limited to Reports (no Narrative Reporting). The structure of these reports will be standard – scenarios, versions, and periods in the columns, with measures, products, and entities in the rows, and some dimensions in the POV. I want to create a universal report where users can define the parameters they want to run these reports for.

For example, one user will run it for metrics A, B, and C, and for all descendants of product X and all descendants of entity Y. Another user will run it for all children of metric D (inclusive), product P, and children of entity Q. I want them to receive the results as Excel attachments as a result of scheduled bursting.