What does that mean SMO ? = SQL Server Management Objects
SMO , when it connects to an instance , is using a ServerConnection object , itself using a SqlConnection object which cannot be used with databases which are not included in a SQL Server instance.
For what you want to do ( if i have well understood ), you should rely on a linked server.
But there is some classes in the namespace System.Data.Oledb which could help you like
For that, i suggest you to have a look at this link :
Have a nice day