How to get action link to pass parameter to 'Is Prompted' column when source column is calculated?

Summary:

Content (required): In Fusion Financials subject area; "General Ledger - Balances Real Time"

I have been following the white paper to develop a dashboard based on General Ledger - Balances Real Time and want to use an action link to provide 'drill down' (open another report and pass parameters to the target report to co-ordinate the result).

My problem is that one of the columns that I need to drill from is based on a calculation, per the white paper, cost centre is based on nested case statements (cf below) to give a meaningful result, and this column is one that I want to use to throw / catch the parameter to an 'Is Prompted' equivalent in the target.