Medical Dictionary; Character count in a Paradox record


I am looking for a medical dictionary -- actually a list of medical words
which I can add to an existing dictionary.  Anybody know where I can get one?
I am willing to pay $$ for it.

Also, I was looking for some ideas on counting the number of characters
entered into a record which consists of numerous string and memo fields.
The database is a paradox database.  I require an accurate count so as to
charge the customer per 1000 characters.

Thanks for any suggestions/ideas.

Aravind Hande