Its not real clear to me that OO will help you here. I think for starters you should simply throw away your code and rewrite it from scratch. Without using any globals. This is a form of refactoring that as a programmer you should be comfortable with. While its a little bit agressive, and some may suggest a less drammatic form of refactoring, a total rewrite can be very beneficial and many programmers and programmer shops assume that the first version of eveything will be thrown away. The result is usually cleaner and better code.

Think of it this way: You already know what needs to be done (always an important issue) you already know at least one way to do it, and you most likely have learned important lessons in how it can be done better. In fact you certainly have, as you have already noticed that using a lot of Globals is just trouble.

So rewrite the puppy. Try not to look at the old code when you do, and certainly avoid cut and pasting from it as much as possible.

The result will be better code and many useful lessons learned.