Hello Binod,
from my experience I can only tell you that inbound Interfaces for creating or maintaining master data are hard to find or rather non-existent. You're supposed to create your master data inside SAP. So if you haven't found anything that could well mean it doesn't exist. It will probably be better and more efficient to write a small proxy program and add that number to your master data. You could check whether you can call some BAPI to update your master data, which would already be quite close to standard.
You could use IDOCs as a more standard solution, but it will probably be more cumbersome to implement and it may use the same BAPIs in inbound processing.
Regards,
Jörg