Hi Alessandro,
I understand that you would like to know how to cosimulate PSpice with Simscape.
From what I can gather from the below MATLAB Answers post, the workflow of co-simulating with Cadence PSPICE systems option is a third party service, and falls outside the scope of MathWorks.
https://www.mathworks.com/matlabcentral/answers/494668-can-i-integrate-pspice-diagrams-into-simscape
So, I suggest you to contact the authors of the PSPICE, as that would be best suited to support you in understanding the workflow to perform the required analysis.
I also found a relevant video attached below which explains how to integrate PSpice with Simulink.
I hope this helps.
Thanks