Where can I find the key to the fields/column drop-down options for the cash.csv file?

Here are the fields/columns for the cash file:

Employee_SSN
Employer_ID
Employee_Name
Birth_Date
Pay_Period_End_Date
Employee_Pretax 
Employer_Contribution
Employer_Match
Pay_Frequency
Hours_Worked
Employee_Roth

How do I remit retirement plan contributions for my congregation/organization?
How do I enter contributions for an employee that I share with another employer and I can't see them in the system?