Since the SET DATABASE TO myDBC is not working, and you have a view based on 2 tables from different DBCs, consider the following. In the primary DBC create a REMOTE view of the table in the secondary DBC. Now create your view based on the table from the primary DBC and the REMOTE view. I also have this same situation and this solution works quite well. You can then go back the the original SP name and use your default value for Regions PK field. The added bonus is that the secondary DBC is not opened.
Mark McCasland
Midlothian, TX USA