Interesting, if very vague puzzle. I can come up with a couple answers that *work*, but they don't seem particularly correct. Something like vowels are worth so many points and consonants are worth so many. Or counting the numbers of straight versus curved lines and scoring them differently. But those don't seem particularly "right".
I suspect it's something a bit more strange, like the letters' translation into Morse code or ASCII values or something like that. It's interesting, to say the least.
Playing around, I noticed that the letters J, K, and Z never appear in the alphabetic spelling of numbers-- every other letter is represented (although "C" first appears in the number "decillion", which is WAY up there!) I found it odd, since "zillion" and "jillion" are often used to represent large made-up numbers, and those two letters (2 out of the 3) aren't even ever used in any numeric spellings, so it's quite fitting! Apparently, we need to officially define "jillion", "killion", and "zillion" so they'll show up!
DaveE