If you do not want to keep track of the soft costs incurred on a matter by matter basis, you can opt for a percentage of the current fees to be charged instead. The global admin cost is setup under Setup > Company Preferences > Configuration Tab. You can also overwrite the global rate by going to the Matter Maintenance screen for a particular matter and adjust the Rates tab, which allows you to an admin costs to some matters and not others. The cost is calculated when you print the actual bill. It is a percentage of the current fees on the bill, including fee debits and credits.