DFF field validation - Include 'Starts with' and 'Does not Start with'

Description
When setting up a DFF in Oracle fusion, please include additional validations
Starts With
Does not Start with

Use Case and Business Need
For our business, we have created DFFs for capturing different information. We need to have validation on the DFF entry that sometimes should not start with a specific set of characters, or sometimes that should start with a specific set of characters
Currently there is no way to achieve this, so we are manually instructing users to follow. But often this gets missed out as there is no systemic way of controlling this validation