Hello,
direct SOAP consumation from XSJS works via the http outbound calls, see here:
SAP HANA Developer Guide for SAP HANA Studio - SAP Library
The api reference can be found here:
You basically need to connect to the webservice by creating the raw request and then work with the response. However, if it is possible i would strongly suggest to switch to pure REST and simple command structure instead as parsing/ handling all that XML load can be quite some work.