Drill Down In Report Designer - Customer Invoice Disputes to drill down to Customer Invoice

SOLVED

In Report Designer I am editing the report called 'Customer Invoice Disputes' and I'd like to drill-down on the Invoice Reference to show the actual invoice. I am able to locate the drill-down function on the properties menu, but unable to find the right instruction to give to the report (to link the invoice reference to show the actual invoice when the curser is on the invoice reference).

Any ideas that may help are welcome!

Thank you

Jenny