Displaying a TreeModel whose branches have different column count in a TreeView

[batman.890825]

Hello there, I have the following logic layer which is also mapped against three SQL Tables:

1. Contract’s Specific Data.
   1.1. Currencies list used for payment. Each Currency also has his own specific data.
   1.1.1. Payees list per currency. Each Payee also has his own specific data.

Contract related data has 4 columns.
Currency related data has 2 columns.
Payee related data has 5 columns.

As you can see if a make a ModelTree so I can display this, first problem I would have would be that TreeViews only use the columnCount() for the invalid index so I the view might not display all the data once the user start expanding the TreeView. Second, since each item has his own header I cannot find I simple way to display each header accordingly to the user current selected index. Any ideas?