[Zope] Using ZOracleDA in external methods

In my application I need to call PL/SQL stored procedures returning data in their OUT arguments. Z SQL methods do not support OUT or IN/OUT arguments. I'd like to call DCOracle methods directly, but I need the very connection object allocated by the ZOracleDA object for the application thread. The majority of database manipulation tasks are done by Z SQL methods, and my external functions (calling these stored procedures) have to share the transaction context. How to get the connection object of the application thread from a ZOracleDA object? I browsed the source code but I am not trained enough to figure out myself. NM