Unicode password input for archives

I have just downloaded an archive from a Japanese uploader (Kasamatsu) but even though I know the password for it (which sadly is 2-byte, aka Unicode), I can't 1) type it directly because the langbar is disabled for password fields ; 2) copy and paste because it won't work, either.

Is there any archiver that supports Unicode password input (WinRAR, WinZIP and 7zip don't) or am I just doing it wrong ? Also, should I change R&L settings to Japanese for non-unicode apps or use AppLocale as well ?

Thanks in advance.

xarchiver