Can you apply a date stamp to CDOs that allow for duplicate entries?

Summary:

I have a CDO that I need to apply a date stamp to. I have a "date created" field that is a field in the CDO separate from the "Created Date" field that the CDO has - because the CDO date field does not allow me to use that field for reporting and it also does not allow me to update it to a specific date if I am importing records retroactively.

The problem is that this CDO is being fed by multiple forms and needs to allow duplicate entries.

My first option was the form processing steps but that can't be used to apply a date stamp because the form processing step requires a unique ID (like email) which would make the CDO a single entry CDO.