Whatever that code is I didn't do it. These forums have issues, and that bit of code you saw is one of them.
The simpler means for achieving your goal is to treat the number as a string and break it into pieces. If you don't know how to use the Flash help documents, then you probably need to learn that first. Search the Flash help documents for the String class, and then look at the various methods it includes. You should be able to find a few possible ways to break your number string into substrings and then write them into the textfields.
It is better if you come here with something to show that you are having trouble getting working than to just say you want to do something and don't know how. People are more apt to help you along with actual problem situations than they are to provide a solution for you (many of us earn our living doing design work for others).