Expression of Ticket Details

{REPORT TICKET DETAILS:<fields>:<expression>}

i have report

[Bill Discount:1, 2]
{REPORT TICKET DETAILS:TTN.Diskon Rate.sum,CA.Discount %}

i test to add expression but not work

REPORT TICKET DETAILS:TTN.Diskon Rate.sum,CA.Discount %:(CA.Discount % >0)}

and i want add expression just filter that ticket Tag Diskon Rate >0, or CA. Discount % > 0 will display value.