Expanding a treeview control

Hi all,

I have built a user-friendly cross-reference insertion dialog featuring a treeview that shows the hierarchy of a structured FM document. The only thing I cannot get to work is that the tree opens the top level when the dialog is built. I can set the 'expanded' property of the top level element to true, but that does not make it expand in the tree view. Is there a command that I can use to make it expand without the user having to click it?

Thanks

Jang