1 Long String - Need to Parse to two text fields

Long time reader, first time question asker . . .

I have to use AS2 to parse a very long string into two text fields.

However - the catch is the second text field can only hold (x) characters (two words) and everything left over is pushed into the first text field.

I've started with two movie clips on my stage:

     mctxtTop

     mctxtBottom

and now I need help. I can create the static string to test, but I'm not sure how to parse only 'some' of the text into one field and what ever is left into the second.

Any help would be greatly appreciated.