Hi,
Adding to above replies, are you calling V.14 and V23 in your custom program or you created your own login in Z program? If standard tcodes are being called, make sure that appropriate restrictions are placed in SE97 tcode for the Z tcode.
In SU24, you will have to add the object to the Z tcode. You will not see it automatically. But make sure that the authority check is there in program (can verify by a ST01 trace).
As Anika said, you can create separate roles for each required sales organization.
Thanks