1. A storage medium containing computer code, which when executed by a computer causes the computer to perform the steps of creating a second file of messages to be outputted by the software from a first file of messages, the messages in the first file being written in a first language, wherein the creating of the second file comprises for each message in the first file, a) applying specified rules to form a second message by changing the character length of the second message, b) filling in any blank characters in the second message with a dummy character, c) inserting characters from the target language into prescribed places in the second message to form a second message having both characters of the first language and characters of the target language, and d) copying the second message into the second file, and executing the software using the second file.