Hope all is well - I was actually in Milan in April/May to start/end a three week jaunt around Italy.
I know historically HP did internally write a uCMDB connector to OCI, but to my knowledge it was written against the legacy OCI SOAP API.
This would not be our recommendation for OCI these days:
The OCI REST API will eventually replace the SOAP API. Right now, it has extensive performance data capabilities that the SOAP API never had, and for capacity use cases it is probably more sophisticated (for example, I am not sure if the SOAP API ever got storage pool, internal volume tooling).
The OCI DWH can act as a consolidation point for the minority of OCI customers who need more than one OCI operational instance. Read only SQL access is available for the DWH's consolidated world view of your infrastructure.
My gut feel is that if HP's canned connector is in fact using SOAP, it would be worth looking at doing your own integration via REST or SQL because the data available may be much more rich.