A simple example of dojo widget composition using InlineEditBox ?

Question

How can I use dojo 1.2 to :

a. define my own widget which inherits from an existing widget (say, the dijit.InlineEditBox widget)

b. programmatically insert a second widget (say a dijit.form.TextArea widget) so that it is the inline editable widget.

I can see how this sort of stuff works with a template html file, but if I want to do it programmatically inside my new widget class's definition, I hit snags. For example, my widget's postCreate function never gets run at all.

Any guidance appreciated. Thank you.