Hi,
How are you integrating Workfront with AEM? Are you using the native integration (details here). Using the native integration you can map custom or native fields from Workfront to AEM metadata fields. These are however a 121 relationship, in that whatever values are recorded in Workfront will be carried over to the relevant mapped AEM metadata field.
If you are needing to do some sort of transformation to the data values, so that the value entered in Workfront is converted into a different value before it is written to AEM, the native integration won't do this. Instead you will need to build a custom integration that will ETL (Extract, Transform and Load) the data from Workfront into AEM. If you have Fusion, you could use this. Alternatively, you'll need to speak to your AEM developers to work out how best to build this integration.
Best Regards,
Rich.