communicating with messages

Hi,
 
I read an atricle a while back which put forward the idea of emulating
try/catch blocks by using the message APIs.
 
The kind of thing I'm looking at is the possibility of wrapping a call to a
procedure in a monitor block and within the called procedure, upon certain
conditions, send a message up the stack to force the monitor group to
activate a particular on-error condition.
 
Sort of...
 
/free
 
 monitor;
 
 // process task...
 processTask();
 
 on-error   TASK_HALTED;
  someCode();
 on-error   TASK_SUSPENDED;
  someOtherCode();
 on-error;
  inTrouble();
 endmon;
 
/end-free
 
 
and in processTask...
 
/free
 
 if haltTaskConditionMet();
  throw('MSG0001');
 endif;
 
 if suspendTaskConditionMet();
  throw('MSG0002');
 endif;
/end-free
 
 
Is this possible? Where would I find examples for this kind of thing? Does
my question make any sense at all?
 
Cheers
 
Larry Ducie