It's possible to use extra parameters in your sql statements. Parameters can have different types, but their names have to be the same as their name in the select method in the facade class.
My guess is that if you can get the Gridview has a Currency Manager somehow attached, then you can probably get the values from it.
I'm in a similar boat...almost the same conditions. NET 1.1 that the datagrid had something called a Currency Manager...it looks like the object still exists in 2.0.
Every operation has to be linked with a method of the class defined in the Type Name property.
Every time a method is called, an object of the class defined in the Type Name property is created by using the default constructor and destroyed afterwards.
The positive side for using an Object Data Source is that the result of a query can be any possible collection (dataset, datatable), array or list of objects.