olap export

while i run the following query i get the followed error can u any help me

SQL>exec dbms_aw.execute('export all to eif file ''a/APPS_ODPCODE.eif'''); BEGIN dbms_aw.execute('export all to eif file ''a/APPS_ODPCODE.eif'''); END; * ERROR at line 1: ORA-36786: File A/APPS_ODPCODE.eif does not exist or cannot be accessed. ORA-06512: at "SYS.DBMS_AW", line 93 ORA-06512: at "SYS.DBMS_AW", line 122 ORA-06512: at line 1
thanks in advance.

Thanks,
SASIKUMAR.J