Our program synthesis APIs are available publicly, but for non-commercial use only. <https://github.com/microsoft/prose> You want to look for API samples corresponding to Transformation.Text capability. This is a more powerful capability than Flash Fill. If you happen to try this out, we'd be very interested in getting your feedback on whether this is powerful enough to handle your use cases, and if not, we would love to be inspired by your use cases for a future version of this technology. You may reach us at prose-contact@microsoft.com.