I also don't know of a specific spread for this purpose (although I do know one for examining a person's given name), but it wouldn't be all that difficult to create one. The English alphabet contains 26 letters. There are 78 cards in a standard tarot deck. 26 x 3 = 78. So each letter would be represented by 3 different tarot cards. But which ones?
As long as one is consistent in their assignment and use of the letters, I really don't think it matters. If you assign the Fool #22, then the Major Arcana covers the first 22 letters of the alphabet.
Starting with W, you could either assign letters across the ranks (Aces, Twos, etc through Kings) or you could assign them up the suits (Pentacles, Swords, Cups, Wands - or whatever arrangement you prefer for the suits).
If you assign by rank, you would have W = Ace Pentacles, X = Ace Swords, Y = Ace Cups, Z = Ace Wands, A = 2P, B = 2S, C = 2C, D= 2W, etc.
If you assign by suits, you would have W = Ace Pentacles, X = 2P, Y = 3P, Z = 4P, A= 5P, B = 6P, etc.
As I demonstrated in the other thread, you can pick one card for each word in the question and find as many names as you can from them. And if you grab all vowels or all consonants, then maybe you aren't meant to know the answer at this point.
And by examining the cards that come up for each name, you can get additional information about the answer. For example, if the question were "What is the name of the man I will marry?" you would pick 10 cards. Assuming you could spell the names Pat and Ralph from those cards, by examining the three cards that spell Pat and the five cards that spell Ralph, you would get additional information about each answer.
Rodney