How to plot I x V product

Hi peeps

I am new to pspice and trying to get my head round some of the functions. I am at present trying to model a pv cell and have have managed to simulate the outputs for different levels of irradiance. I am now trying to determine the max power point and the power locus. This is just basically a product of Y x X. The problem is that I have absolutely no idea how to do it. Any chance anyone could point me in the right direction. I realise this is probably just a simple command, but if you do not know then you do not know.

Cheers

Dave