Oracle has a query that selects the existing indexes of a table. For example:
SELECT * FROM user_indexes WHERE table_name = \'CM_WCEL\';
But
To get the complete DDL for each index, use dbms_metadata.get_ddl():
select index_name, dbms_metadata.get_ddl('INDEX', index_name) as ddl
from user_indexes
where table_name = CM_WCEL';
The DDL is returned as a CLOB. Depending on the SQL client you are using you might need some configuration changes to be able to see the complete code. e.g. in SQL*Plus you need something set long 60000 before you run the select statement.