Keeping child windows in their place

I've created a bunch of custom widgets for my latest application.

Now I have a thought of expanding them to include setting child windows within these widgets, however before I attempt it I have a bit of a problem in concept.

How oh how do I keep those darn child windows in their place?

Say I have a scrolling area, nothing simple just a boring old widget with scrollbars. Now if I add a child to this widget, i would say want them to wrap vertically, and I might add a bit of padding between the children and the parent for looks.

Now, when this is resized or something I may have to move the children or whatever (this is a bad example I realise but I'm too lazy to come up with another.) should I just enumChildWindows() and simply relocate them according to my rules and numbers?

I guess, trial and error for this most likely but I really cant think of any other ways so I have nothing to fall back on if this method is an error.

Cheers guys

If I remember correctly there were some good tutorials and code samples on this exact requirement in codeproject.com.