Israel & Yehuda, I think this are the first steps. But the language should be French, because the guy was a frenchman.
I think too, that this was already done with small results, because the gold is still hidden.
From the army I remember, that we had some kind of templates, that you put over the text. It is written quite semetric.
Another method was intervall counting and a matrix (i.e. A1 is b2)
But perhaps there is no content at all in it and it was his last way to make fun of the people who killed him.