PSR can be found in field #251 of a .JCP file (the same way that Prime Power is in field #251 of a Brisnet file.)
When HDW is persisted as the Data Vendor on the User System Definitions Screen - and you have one or more .JCP Files loaded into the program via the DFM Card Loader - when you click either the Calc Races button to run a Calc Races routine - or if you click the Build Database button to run a Build Database routine:
Numeric Value, Rank, and Gap for HDW PSR is written to JCapper's text files and tables.
From there, to "grab" HDW PSR in the UDM Wizard:
In Playlist File Mode: Select Prime Power from the factors drop down on the Modify UDM Screen of the UDM Wizard.
In SQL Mode: You must have selected Prime Power as a factor in the SQL Factor Setup Wizard. From there - if for example you had assigned Prime Power as factor F31 - you would simply reference the VALF31, RANKF31, and GAPF31 fields of the StarterHistory table in SQL Expressions driving your UDMs and/or Data Window research.