Double-byte to single-byte conversion

Does anyone know if it is possible to write a macro in Keyboard Maestro which would be able to take highlighted double-bye text and replace it with the single-byte equivalent?

I handle a lot of Japanese text that contains numbers written in double-byte characters, and I'm looking for a quick way to convert these to single-bye characters.

Any advice here would be hugely appreciated. Thanks.

I've had this same need myself, and this is one type of macro I came up with to solve it:

Double-Byte Numbers → Single-Byte Numbers.kmmacros (3.8 KB)

Much appreciated, gglick. Many thanks.