DataRow -> BindingContext.Position

I can get the DataRow that I want to work with from my DataTable by using the ParentTable.Rows(x).GetChildRows("MyRelation"). How do I take that row and then determine the position of it so that I can set that to be the current row in my BindingContext? I know I can loop through all of the rows to find the one I need, but is there any easier way to do this?

Thanks!!