The following steps sets the CICS Resource Definition File Path field, so that you can use a datastore:
If a CICS resource definition file already exists and you want to use this with the Performance and Availability Cluster (PAC) then import the file to the database using dbfhdeploy and the path specified in the CICS Resource Definition File Path. For example:
dbfhdeploy -quiet data add <PATH>/dfhdrdat sql://MYPAC/VSAM/dfhdrdat?folder=/RDEF