You will have to do some coding modifications.
You need to look at every token in the string, if it starts with numbers, leave it alone. If it is letters, propcase it. That would be the easiest and add some rules about apartments.
I'm not sure why you have 4 letter rule. "12 South MAIN Street" may not look so good.
Other option is to do some searches for modules with regex (regular expressions). There are a few developer sites which may sell these or provide as shareware. And then just call the external module from VBA.
-stormin