There are a few limitations with HANA stored procedures in B1UP (SAP SDK).
1. SAP SDK does not support the Out parameter in Hana stored procedures. So you need to create a simple stored procedure and call it, as shown below.
CREATE PROCEDURE U_BOY_TEST LANGUAGE SQLSCRIPT AS BEGIN SELECT TOP 1 "CardCode" FROM OCRD; END; ***
In your macro, you can then call the stored procedure using the SQL() command, like this.
@STORE1 = SQL(CALL U_BOY_TEST)
2. SAP SDK (and therefore B1UP) does not support a multi-value back system.