You can use any mechanism that you like to select folder pages, but I presume from your e-mail that you are looking for ideas for an alternative because tab-folders are looking a bit "dated"?
Incidentally, as you are using Windows XP, are you aware that you can enable the Windows XP GUI Look & Feel in Progress from 9.1D07 onwards? To do this you install a "manifest" XML file in the progress bin directory, set a registry entry and start Progress. Then all button, radio-sets, check-boxes etc. will automatically appear in the Windows XP GUI style. Here's the link that explains it:
http://www.progresstalk.com/showthread.php?t=68712
As an alternative to a tab-folder, what about using an explorer style interface? This would consist of a series of hyperlinks down the left hand side of the window. The first link at the top would select page 1, the second page 2 etc. See the attached screen shot for an example.
This would work perfectly well but you do say that you would want this to be reusable, so you would need to create a new SmartObject. If you wanted the new SmartObject to have properties settable via a property dialog it can get quite complicated but it possible to do this entirely using the 4GL. If you need any help in this area, drop me a line.
Another alternative is to use an Outlook style list bar. This is the selection object displayed usually on the left in the Outlook window. Each icon can represent a page to select. SmartObject pages don't have to be consecutive. You can group objects on pages 5-6 and 9-12 and the ADM will be quite happy. All you need is a machanism to select the appropriate page at the appropriate time.