I do not remember trying to solve this problem or hearing of anyone trying to solve it within the stylesheet. I can't say I know it is not possible, though. I do remember people talking about trying to code a stylesheet (I can't remember for sure, but I suspect it was in FOSI not Styler) to react to the length of a string (possibly within a table cell). It was hard. Everyone advised against it, or at least added to the list of challenges that would have to be met. Essentially, you are recreating some portion of the composition engine itself.
All that said, don't take my word for it. There is a very active PTC/User hosted mailing list called "adepters" after a very old product name for what is now Arbortext Editor that you should consider joining. Lots of Arbortext gurus hang out there 24/7/365 helping with (or at least commiserating over) problems. You can find subscription information here: http://www.squidoo.com/arbortext#module87462061
Maybe someone there has wandered further down this path (or has a better memory) than I have. They will surely help if they can!