Hi Henk,
Officially only loading spatial data from HANA and Oracle is certified with Data Services 4.2. When loading from Oracle, Data Services is generating a Sql statement that contains a function to convert the Oracle spatial field to WKT. See http://en.wikipedia.org/wiki/Well-known_text
You could try to build a view in Sql Server that does the same. The geometry field in HANA is recognized by Data Services as a long (Hana sps7) or blob (Hana sps8), so you need a query statement that converts the output of your spatial field from the view into the appropriate data type in Hana. I'm not sure if its correctly loaded into Hana, but its the best you can do with the latest Data Services version.
Another option would be to load Esri shape files into Hana, but thats a manual operation.
Best regards,
Stefan Koster