A better hack would be to do image recognition on the board and have an arduino or lego play for you. Just loading your OS's dict[0] in a trie and filtering using the characters on the board, you can already pretty easily win games without even using any strategy (just try the longest matching word with a letter or two you don't own), add a very basic AI to get the board painted in the shortest possible number of moves and you should be done (nb: an extension would be deciding on suffix-pruning, as I believe letterpress doesn't allow suffix extensions of already-used words)

[0] using letterpress's own dictionary file would be better as it'd avoid words which are in one but not in the other.