Can this be done? Or does the DSP only work with SQL data sources?

In I have these lines:

I can run queries in Analyzer, and there are no errors in the log so I think it's loading the DSP OK, but it isn't doing any of the %{} substitutions.

(If I use an invalid DynamicSchemaProcessor name, eg , I see errors in the log which is why I think it is loading it OK)