Changing value from $ to Yen

I have a sheet with lots of scattered data points which
are in US $. I would like to replace all of those with
a converted Yen value.

Is this possible?

Also, does anyone know of bugs in the password part
of excel that do not allow a Japanese user to save
the file? Even if that person knows the password.
Any tricks to get around it? I can modify and save
a password protected workbook but a Japanese
user cannot?

thanks for any help