To do a non-boolean conditional insert in SQL Server (the "where exists" clause is best for boolean), use the "where in" clause along with an inner join, in the following form:

INSERT INTO [Destination Table]([Destination Field1],[Destination Field2],[...])
SELECT [Origin Field1],[Origin Field2],[...]
FROM [Origin Table]
WHERE ([Test Field A, could be from origin] Not In (select [Test Field B] from
[Test Table, could be destination]));