I'd need more detail about the table structures to help you with this. A trigger strikes me as a bit overkill and won't really solve your problem. To really help you further I'll need the following info:

The structure of the tables involved.
What sort of relationships exist between the tables (1 - many, 1 - 1).
The structure of the view.
What are you updating from (an application, just a SQL query, etc...)?
What fields are you trying to update.