Insertion-Index
This numeric property affects the position where a new Tab is added to a Ribbon control when the Tab-To-Add property is set. If this property is set to a positive value, the Tab is inserted immediately before the Tab the property refers to. When set to 0, the new Tab is appended after the last existing Tab.
 
Example - Modify a Ribbon control to add 1 page at position 1
...
  modify screen-1-rbn-1-hdl 
         insertion-index 1 tab-to-add "Page one"
...