advice on updating a calculated column (i.e. read-only) in datagrid

[astro]

I have a non-updatable column in a SQL:-Server view that represents a 1-to
{0,1} relation with a child table.

I want the end-user to be able to change this value. This view is generated
with the following SQL code:

create view dbo.v_leads_person
AS
SELECT
p.personID,
p.companyID,
p.fname,
p.lname,
p.gender,
p.phone,
p.roleID,
CASE
WHEN mt.personID IS NULL THEN 'Not'
ELSE 'Yes'
END as mailTo
FROM person p LEFT JOIN mailTo mt ON p.personID = mt.personID
Ideally - the updating stored procedure that is called by the dataAdaptor
takes care of this with it's own custom code (written by me).

Currently the dataAdapter ignores any changes to the column and submits the
original back to the database.

Is there a way to over-ride this dataAdaptor behavior without resorting to
datagrid specific events?

Also...
Is there a 'best practice' regarding this scenario (design pattern?)? This
child table is used to enfore only one person being the 'mailTo' target for
a given company. There can be several contacts per company - but only one
can be designated as the 'mailTo'. There are other means of enforcing this
business rule - but having the business logic in the database is most
appealing to me from a design (and maintenance) perspective.

Thanks ).