Spectremdl - Equation for Capacitance calcualtion

Hi, 

Here is the netlist I wrote it for capacitance calculation. 

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simulator lang=spectre insensitive=yes

parameters
+ f0 = 1M f1 = 5M f2 = 10M // keep same delta
+ vvp1 = 0
+ vvp2 = 0

******************************************************************
include "./call_lib_spectre.scs" section=typical
******************************************************************

X1 ( 1 2 ) cap_mim w=30u l=30u m = 108

Vp1 1 0 vsource dc=vvp1 mag=0.1
Vp2 2 0 vsource dc=vvp2

VoltSweep_p25 ac freq=100k dev=Vp1 param=dc start=0 stop=1 step=1

simulator lang=spice
.print ac Cap1=par('IM(Vp2)*IM(Vp2)/(2*100k*3.1415926*II(Vp2))*1e12')
simulator lang=spectre

saveOptions options save=all pwr=all currents=all

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To print the output capacitance I used SPICE format. 

But I wanted to do the same in SPECTREMDL and I wrote the following.. 

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alias measurement acrun {
export cplx Cap1

run VoltSweep_p25

Cap1 = (mag(Vp2)*mag(Vp2)/(2*100k*3.1415926*im(Vp2))*1e12)@cross(sig=V(Vp1)-1)

}

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But here is the warning

WARNING (MDL-1565): validate object failure -- parameter or terminal 'Vp2' not found in specified scope.
WARNING (MDL-1101): 11: MDL expression for identifier 'Cap1' can not be evaluated due to previous errors.

I am novice in using spectremdl and currently learning it. Anyone can help me where I am wrong in putting expression for Cap1 in spectremdl...

Thanks, 

Hareesh