Indirect Property Bindings

I have a docked view that passes sample information between itself and the main view. I have it set to a bi-directional property view (which works perfectly for one sample).
I need a way to dynamically set the sample number for that property binding but I don’t see a way to nest the paths. Is there a good way to do that?
I’m sure I could do an expression binding but I’d lose the bi-directional effect. I’d like to stick to a property binding if we can.

Why aren’t you using a custom session property?

I had a dock set up already with parameters being passed so adding one more to the list was the easiest way to pass data (instead of using a session property I mean). What I think I’m going to do is just have the expression work done in a separate property and then bi-directional bind to that. I think it’ll work. I’ll mark this solved if it does.