On ome of my apps I have to open four databases on one Form, 2 databases with the same name and the other 2 have the same name betwen them.
I do this:
The first database is opened when app starts and set has the current database with SET DATABASE
whe I open the other Databases, I use Set Database to work with this, then I close it, open the 3th database and again with set database work with it and equals with fourth database.
At end of using the databases and closing them, I do SET DATABASE to the main database of my app.
I can't find a better way to do this, but this work for me and I think this can work for you

Hope this help

Mauricio