I'm not sure what you're asking.
It's not possible to accurately simulate a solar cell and nor is it necessary most of the time.
A solar cell looks like a diode with a constant current source connected in parallel with a couple of resistors.
You should be able to get the value of RS + RP using an Ohm meter with a test voltage below the photocell diode drop voltage. I'm not sure about RS, I think you should be able to vary the load, maybe Norton's therum can help.