There is no report in xRC which can give you this information.
Instead, I recommend using either DSPF or HSPICE as an output netlist format. Then be sure to use the RLAYER in the PEX NETLIST statement and make sure no TICER reduction is turned on and no VIA reduction.
See the following SVRF statements in the SVRF Manual.
PEX REDUCE TICER/ANALOG/DIGITAL
PEX REDUCE VIA RESISTANCE
Thanks for the quick reply!