Given a leakage power equation

P=a0 + (a1)*vth^2 + (a2)*vth^2

where a0,a1,a2 are the fitting parameters and vth is the threshold voltage. How do I extract these values using LTSPICE?

 

Extract from where?
Threshold voltage of what?

 

I run a Ltspice simulation of an inverter by varying the threshold voltage(pass a Gaussian pdf and perform MC simulation)
Now keeping SPICE simulation as a reference, I want to verify the above mentioned model...But how do i extract those fitting parameters using SPICE simulation?