Start up the extproc agent within a session. This package can help you debug external procedures.
Subprocedures: STARTUP_EXTPROC_AGENT This starts up the extproc agent process in the session
For full documentation of the packaged procedures
above see the Oracle Manual:
"Oracle9i Supplied PL/SQL Packages and Types Reference"
or the book Oracle Built in Packages by Steven Feuerstein et al