Insert indented listbox item

From REALbasicWiki

The InsertRow method has an undocumented (as of 8r4) parameter that indicates the indent level of the inserted row when it is used with a hierarchical listbox.

Listbox1.InsertRow 4, "New Item", 1

This will insert the text "New Item" at the 5th row (listboxes are 0-based, after all), and indented 1 level