Yes, JET supports joins on calculated fields.
Method 1:
Create a query with the calculated field and save.
Create another query, using the first one as an input "table" along with the
other table.
Method 2:
Switch you query to SQL View, and type the expression into the FROM clause
directly.
Either way, there seems to be a bug in JET such that it processes outer
joins on calculated fields as if they were inner joins.
