GET API identification to retrieve transaction details using DFF values

We need to search for a transaction in our current interfaces using the DFF values stored ,say for ex. Confirmation number which is stored in Interface_Header_Attribute5 of the transaction header table. I was wondering if you could help us in identifying an appropriate API through which we could replicate this functionality in fusion as the below API seems incapable of doing so. Let me know if my understanding is incorrect.