Shared Datasources that use dynamic DB connection strings

Is it possible to create ashared datasource that uses a dynamic DB connection string? I can't seem to get it to work. The db connection string is as such (server and DB names changed):

="Data Source=" & IIF(Hour(TimeValue(Today)) Mod 2, "FirstServer;Initial Catalog=exampleDB", "SecondServer;Initial Catalog=exampleDB")

I can see why this wouldn't work as a shared datasource if I was using a report-specific parameter, but I'm just switching the server/DB based on the time. Anything special that I need to do to get this to work?

[568 byte] By [LJohnson] at [2007-12-17]