How to make setting for internal transfer

Hi experts,

          My use case is to create a outgoing bank payment file for ebanking purpose.

          My bank accepts Internal Transfer between two accounts withing the same bank. (free of charge )

          Here are my problem.

          1. I don't know how to create a payment medimu format for internal transfer.

              (I have already created payment medium formats for domestic transfer and international transfer).

          2. I don't know how to add a new Payment Method Detail in Outgoing Bank Transfer prosess.

              Please refer to the below screen shot.

             As per my knowledge, I have to select "Internal Transfer" (or some other name) to match with the payment medium format created for internal transfer.

             Any help is super appreciated.

Special Thanks in advance,

Fred