There is always at least one lateral BJT in a CMOS device.
There are even more in JI. But the qualities as an amplifying
element are always deliberately degraded in order to make
the MOS behave more ideally.
Body is base, gate is field plate, S/D are E/C. You would
be well advised to pull your own data across the full temp
and supply range, and you'd have to take a wild guess at
process variability of this non-valued non-library element.
In most cases you will not even be able to get a foundry
sourced model, or a usable symbol. You can overcome this
by personal effort. But you might prefer to use a flow that
supports the device, especially if your reference is supposed
to have good accuracy, stability and production tolerances.