Hi Roger,
What is my understanding is you have a KPI ETL Calculation and you would like to display KRI Details of explanation on run time right?
To Achieve the above requirement you can go with " On-demand sub report" Concept.
With that you will create a report with 'KPI ETL calculation' in main report and 'Details Explanation' in sub report'. In crystal report we have an option to pass main report values(KPI values) to sub report. also we can link main report and sub report with common fields.
After provide the link, if make the sub reports as "on-demand' then the detail sub report will execute only when you click on them only.
Thanks & regards,
Naga.