1) here the mod_authnz_lap to put in /opt/lampp/modules/* :
2) add in the /opt/lampp/httpd.conf :
LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
3) an example for httpd.conf to auth with ldap
* I ve recompiled xampp-apache with --enable-authnz-ldap