importing P/G pins into Encounter with .def file

Dear all,
I have been trying to get the pins (VDD and VSS) in the extracted .def file from cadence into Encounter. however, when i do the defIn cmd, it keeps giving me this error:

Pin "VSS" is not created because it's not in the netlist and also not a P/G pin.

>> I know it's not declared in the Verilog netlist since it is power/ground pin. Why does Encounter not recognize it as a P/G pin. even in my .conf file, i have this:

set rda_input(ui_pwrnet) {VDD}
set rda_input(ui_gndnet) {VSS}

so if anyone has experience the same, please let me know. thank you very much.
regards,
chhay