How can I use my own Bapi in IdM 7.2?

Hello,

We use a IdM 7.2 and CUA scenario. New I have the challenge to modify the HCM infotyp 105 subtyp 001, when I will add a new member in my Idm 7.2. My ECC 6.0 EHP 6 is member of the CUA, so I have only defined  the CUA in my IdM.

My developer made me a Bapi to change the infotyp. So my question:

How could I call my own Z-BAPI in my Idm? I think, I have to use a custom pass with "pass typ" ToSAP, haven't I?

Best regards,

Hans