Take the script, rename it to "twitter2lj.pl", replace TWITTER_USER, TWITTER_PASS, LJ_USER, and LJ_PASS with your username(s) and passwords. Set it up via cron (or some other scheduling application) to run at 23:59 each evening.
Yes, I'm running it from my Mac (which is Unix-based). Yes, it will probably run on Windows. No, I don't know how. If anyone uses this or something similar on Windows, feel free to leave a comment here so others can benefit from the knowledge.