Exception handling in SQL Script procedure

I am trying to make SQLScript procedure with a nice way of exception handling. The idea is to catch:

1) System exceptions

2) Logical exceptions

and send info to the output.

For the moment i have:

CREATE PROCEDURE<schema>.TEST01 (OUTes_errorNVARCHAR(50))

LANGUAGESQLSCRIPT

SQLSECURITYINVOKERAS

BEGIN

DECLAREMYCONDCONDITIONFORSQL_ERROR_CODE 10001;

DECLAREEXITHANDLERFORSQLEXCEPTION

BEGIN

es_error := 'err';

END;

<if logical error>

SIGNALMYCOND;

</if logical error>

<test of SQL error>

INSERTINTO<schema>."TMP_TEST01"VALUES(1);

INSERTINTO<schema>."TMP_TEST01"VALUES(1);

</test of SQL error>

es_error := 'ok';

END;

The problem is in the fact, that i can catch errors, but i can't distinguish between them.

Of course before "SIGNAL MYCOND" i can put text of error in variable and send it to the output, but the main problem i can't get code of SQL exception. How can it be done?

In SQL Script documentation there is something like :

DECLARE EXIT HANDLER FOR MYCOND SELECT ::SQL_ERROR_CODE, ::SQL_ERROR_MESSAGE FROM DUMMY;

But complier can't find corresponding columns in DUMMY...

So, does anybody know how SQL exception code can be caught?

PS: SP05 rev 52.