There is no way a customized Target Mapping could be created for Schema other than Profiles, ACS doesn't allow that.
If you have access to Support Portal (https://support.neolane.net), you could raise a ticket with us. We could then discuss this further with our Product Engineering Team and get it raised as an Enhancement Request for future Releases.
I believe you are referring to Profile details to be added in ACS using an external source.
- One standard way is to upload a file, or 'Import a List' in ACS terminology.
This option is available for use under Profiles & audiences section -> Imports
- Just like ACC, FDA Implementation could also be done in ACS to import data. An 'External database' type of External Account could be created and data could be imported into ACS. Kindly note, this would generate a customized Schema within ACS.
You could then reference that Schema in your Workflow, or maybe link it with the standard Profile Schema.
I am not very sure of the implementation details and feasibility of the same, so far, I haven't come across any client implementing something like this for Profiles.
Let me know if I have misinterpreted your query by any chance.
I think he meant creating a new target mapping to contact Users instead of Profiles for example. I'm also interested if we still can't create target mappings with a different resource than Profile to send for example, alerts to users.