Is it possible to use DFF to calculate for the specified journal amount?

Summary:

To provide context, business is using General Ledger Module to create AR transactions and account it accordingly.

Specifically, they are using DFFs to define the Transaction Type, Party Name, and etc.

Now, we are aware that DFFs can be used to define LOV, or to define a textbox value. However, is it possible to use a DFF to calculate a specific percentage amount? In Addition to above, is there a functionality/configuration where the Journals can generate an accounting line after posting the Journal?

For example:

• User will select a a Tax Rate DFF from the Journal Header(i.e. 1%, 2%, 3%…)