binding array property? - syntax?

[movinator]

Hi,

I'm working on a collectionview, where the items have a fixed array property. scalar properties are rendered as expected, so I know templating and viewmodel do work. Access to array property does not work and I wonder, what the correct syntax may be.
The array instances have a scalar property and a property which is the result of a function call.

I tried "{Binding Crowd[0].foo}" for the scalar property and "{Binding Crowd[0].bar()}" for the function result.
None of it works.

What is the right way to access indexed properties?