Changing numbering in story view

What I would like is the ability to choose a STARTING number for the a scene other than 1 (like choosing a starting number other than 1 for the start of an ordered list.)

The problem we keep running into is that we have, say, 7 modules in a series. Each module is its own storyline file, because we need to track them by module in our LMS (someone might only be assigned modules 1-4 and 7, for example). The client wants the numbers on the slides (so they can tell someone to "go to slide 14" in a module and we're all on the same page.) But, it's very confusing to see "1  Module 4    1.1 Introduction   1.2 Objectives...." etc. The client, reasonably, wants these numbers to be 4.1, 4.2, 4.3, and so on. However, this seems to be impossible unless we turn off autonumbering altogether and manually number our slides. This is VERRRRY irritating though because when a slide does need to be deleted or reordered at any point in the development cycle, you need to manually go and renumber all of the slides. So, an option where you get to pick WHAT number the scene is called would be very very appreciated.