How to change database connection in a module ?

Hi all,

For a module, I need to change the database connection, not only the database, but also the server which is Microsoft SQL Server...

My first idea is to dupplicate Database.php (eg: DatabaseMs.php) and change all $GLOBALS['TL_CONFIG']...
After I may use :
$this->import('DatabaseMs');
$objDB = $this->DatabaseMs->prepare("SELECT id ...

Is it a good idea ?

I answer myself : this is not a good idea :(

What happened?