Store test data on jenkins

Can jenkins store custom variables on the server its running on? Essentially what I am doing is passing parameters into a jenkins setup job. These parameters will then be stored in a properties file and used as test data.

For example, I run a job to update a properties file with the current number of active users on the system. I then have tests which access this properties file and confirms the amount of users. Can this be done? Is it bad practice? I know jenkins has a number of environment variables that can be assigned but can it be done with custom variables?