How to escape values in radclient?

Hi, I am planning on using radclient in a quick authentication script until I could fix an authentication library. I thought of using radclient in a shell script for the authentication task as it seemed fairly simple, however I wasn't able to figure out how to escape values that are set by the user; namely User-Name and User-Password. I tried checking the manual page but I haven't had any luck with that. It doesn't seem to have been mentioned, but I'm fairly sure this scenario was considered. TIA, rany