Multiple ODBC connection

Hi all,
i'm back to Lianja.. but not my head.. :-)

I'm sure this has been discussed before, but I don't remember....

I have 2 identical databases on MS SQL, one test and one production.

I would like to be able to switch between the DBs via a configuration file external to the application.

It seemed to me that you could set in the ODBC connection of the virtual tables a variable: ?myOdbc

Then, from code:
public myOdbc
myOdbc = "WMS_xxxx"
Attachment 2646

but don't work..
any suggestion?
thanks
Fabio