IBM has not implemented the same support for all SQL syntax related to stored procedures in every supported language. For example, you cannot create COBOL stored procedures that use result sets or the EXEC SQL syntax that supports that functionality with the workstation version of DB2 LUW.
There is no support for structure, array, or vector parameters using the DB2 native precompiler. However, there is much more flexibility when using the OpenESQL preprocessor and an ODBC connection.