The locale is fr_FR.UTF-8

Configuration is :
    dos charset = cp850
    unix charset = UTF-8
    display charset = UTF-8

When user has non ascii character, I can't find a nice way to get him access his
profile.

First try :
    root preexec = PROFILE=/opt//share_Profiles/%U ; if [ ! -e $PROFILE ]; then
mkdir -pm700 $PROFILE ; chown %u.%g $PROFILE;fi

The directory is created with __ instead of each non ascii char, but then with 

logon path = \\%L\Profiles\%U

it can't access it's profile like if %U was not interpreted the same way in the
[global] section as in the [Profiles] one.

2nd try
I tried with %u at both paces, did not work better

3rd try
using %U in the preexec
setting sambaProfilePath in the LDAP to the username with non ascii chars
replaced by __

works fine but it's problematic if we have to add an entry in the LDAP for each
user with non ascii chars in his name. More, we won't be able to add an user
with usual interfaces.