Ciphertext Analysis with Excel?

Hey guys, I have written a quick spreadsheet that does a character frequency analysis on a given ciphertext string.

I have a question on improving the functionality:

Q: Is there a way to print out the ten most frequent bigrams (two letter combinations) and trigrams (three letter combinations) with a formula or VBscript?

I have attached the file for your review.

Thank you in advance for your assistance.

-JJ