You only know 1 character of a 30+ character password? In that case, there is no point even trying to brute force it, since 29 unknown characters is far beyond the scope of what is realistic.

I would also use btcrecover as suggested above to do this, but you need more information to go on. What did the password look like? Was it completely random or did include names, words, dates, etc? What character set did it use? Uppercase, lowercase, numbers, symbols, etc?