You can validate a parameterized Simscape™ Electrical™ component by comparing its behavior to the data from a specialist circuit simulation tool that uses a manufacturer SPICE netlist. Make sure to create a test harness for the component that validates the data across relevant operating points and frequencies.
If you have lab measurements of the device, or data from another simulation environment, you can use this to tune the parameters of the equivalent Simscape Electrical component. For an example of parameter tuning, see Solar Cell Parameter Extraction From Data.
In Parameterize an Exponential Diode from SPICE Netlist, parameterization from a SPICE netlist is relatively straightforward because the netlist defines a single device (the diode) plus the corresponding model card (the parameters). Conversely, a netlist for an op-amp may have more than ten devices, plus supporting model cards. In principle, it is possible to build your own equivalent model of a more complex device by using the SPICE-compatible blocks in the Simscape > Electrical > Additional Componentslibrary. Connect the components together using the information in the netlist. Before embarking on this, make sure that the Additional Components sublibraries contain all the SPICE-compatible component models you need.
If the device models you wish to model are complex (hundreds of components), then cosimulation with an external circuit simulator may be a better approach.