Hi Andreea
I have not tried the SAP RM message protocol on the SOAP adapter in HCI. I've checked the HCI's online documentation and there isn't anything there on QOS URL parameters. However, there is a Wiki listed there, which talks about it in the "Interoperability with 3rd parth products" - you can maybe try adding &QualityOfService=ExactlyOnce to the URL configuration in the logical port.
Another option would be to try using normal SOAP 1.x protocol instead on both sides. I know definitely that SOAP 1.x works fine in HCI's adapter.
Regards
Eng Swee