>I want to change the value of a field in a particular record in one DBC based on the result or event in another DBC.

I would probably use an UPDATE TRIGGER that is a function call to a SP in the DBC. In that procedure, I would then update the other table in the other DBC. Keep in mind the UPDATE TRIGGER fires if any field is updated in the record, so I would do some checking with the GetFldState function[row or table buffering required].