Declare CLOB as a host variable and use it in SQL statement in PLI

Hi guys,
 i get compile error when I use the code 1, and SOC4 error when I use the code 2. This is in language PLI (mainframe)

1) Compile Error: UNUSABLE HOST VARIABLE HOST_VAR
I am declaring HOST_VAR as 02 level.

DCL  01 STRUC,
             02 VAR1               CHAR(10),
             02 VAR2               CHAR(5),
              02  HOST_VAR USAGE IS SQL TYPE IS CLOB (10M);

EXEC SQL
  SELECT :HOST_VAR FROM SYSIBM.SYSDUMMY1;

2) S04 error  : Indexing or subscripting outside defined limits
When I am declaring  HOST_VAR as seperate 01 level

01 HOST_VAR USAGE IS SQL TYPE IS CLOB (10M);

EXEC SQL
  SELECT :HOST_VAR FROM SYSIBM.SYSDUMMY1

any ideas?