nah, the regex will be ok, a lot faster than the actual pubkey derivation

if there is a way to optimize the regexp to that specific thing before you run it that would help, i mean, it should just be generated code or a closure that is derived once and runs each attempt 

 and yes, you should dedicate a machine to it, if you have one... it's gonna take weeks, maybe months 

 remember the old expression "man-month" well "machine-month" hehe