exception propagation for a distributed call

["REH" <spamjunk@stny.rr.com>]

I need to implement something that has probably already been done
hundreds of times.  I have to implement some distributed calls (i.e.,
across sockets, arinc ports, separate memory partitions, etc.).  I need
to trap any exception that may occur, and re-raise it for the caller,
like CORBA does (though I cannot use CORBA, RPC, etc.).  I also do not
want to replicate a lot of code in each exception block.  What I have
so far is to create a procedure that will take an exception occurence
as a parameter and call it in each exception block at a "when others
=>" arm.  The function returns an enumeration value for the exception
which can be marshalled across and re-raised via a case statement.
What I cannot figure out is how to convert the occurrence in a portable
way so I do not have to use compiler-specific features.  I know I can
convert it to an exception_id, but how do I determine which exception
the id is for?  Is there a way to get the id of an exception without
raising it?  Or, is there a better way 

Thanks,

REH