I'm a newb, so feel free to ignore me but I think as you add data this will get more and more complex. My guess is a reference to the parent in the child's data set would make this easier.
edit: something like this:
edit2: I misread what you meant. You already have a reference to the parent. I thought you were saying you had an field for whether the entry was a child or not.
Last edited by Prime8; 12-11-2012 at 12:04 AM..