Brainless is not looking for pubkey #110; he is looking for #120's pubkey inside 2^110 range via shifting #120's pubkey. Ultimately he has shrank the range by a factor of 2^10 = 1024 but needs to run the program for each pubkey or integrate runs with the 260 pubkeys.
How do you shift or shrink a range? I think I seen that before.
You subtract from the original pubkey you are searching for.