A couple of things:
First, I believe you have confused "Trimbach" an Alsatian winemaker with the term "Trocken" which (here's more confusion) by itself means "dry" but when used as a prefix as in "Trockebeerenauslese" is the indication of the sweetest of German wines (familiarly known as TBA).
Secondly, TBA wines, while high in sugar at harvest, are fermented to be a sweet dessert wine as you note. Therfore they retain much of that sugar - it does not convert to alcohol. Sweet German wines are generally low in alcohol, as low as 7-9%.
For the original poster, a couple of things:
"Proof" is not used for wines. "Proof" is actually double the alcohol content - 80 proof whiskey is 40% alcohol. A 13 proof wine would be only 6.5% alcohol. That's ale or stout.
Secondly, try looking for a late harvest / late picked Zinfandel. They can approach 16% alcohol.