If you call your map from inside an Orchestration you can use a simple .net component to read the btsserv.exe.config file. Not real sure if that would work inside a pipeline – I think it would though.
As an alternative you could always use a .net component to read from a config file at a known location.
In any event, you’ll need to use a .net component inside a scripting function before the database functoid to read the value and pass it in.
Hope this helps.