FreeRadius + OpenLDAP (SMD5) + Windows XP

Hi, I got a simple question but I don?t find anything to answer it. Situation: I got a database OpenLDAP which contains users info, mainly ?uid? and ?userPassword? crypt with SMD5 and I can?t modify this encryption type. I want Wireless users to have to authenticate to access the WLAN without installing anything on users' PC (mainly Windows XP PCs). Question: Does anybody know if there is a way to authenticate users using this password ? I tried using a clear-text password and that works but I cannot and don't want to change userPassword encryption. Thanks a lot for any idea/help, Romain Mercier