Tab-To-Add
When this property is set, a new Tab is added to the Tab-Control control. The value of this property represents the title of the new Tab.
Multiple Tabs can be added at the same time, by enclosing their titles between parentheses.
 
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"
...