How to measure current probed by isub() command using spectre xps ?

Hello All,

I am trying to find leakage of different instances/subckts using spectre xps.

I tried using 

chk1  dyn_subcktpwr   inst=[*]        port=[*]        depth=4 time_window=[36n 37n]

It dumped an empty xml file.

Then moved ahead with spice commands as under:

For 

.probe i(vvdd)
.probe i(vvcs).

I am measuring them as under:

.measure tran leak_vdd_1 avg i(vvdd) from = start_time to = end_time
.measure tran leak_vcs_1 avg i(vvcs) from = start_time to = end_time

But how to measure current for below probe which used isub

.probe isub(SEGIOX2.VDD)
.probe isub(SEGIOX2.SEGIO0.VDD)
.probe isub(SEGIOX2.REBUF.VDD)

I tried following ways which did not work.

1) .print isub(SEGIOX2.VDD)

2) .measure tran leak_vdd_2 avg i(SEGIOX2.VDD) from = start_time to = end_time

So any help on how to dump current probed by isub ?

Thanks,

Roopak