Well, that does not look so easy to me (that's why I'm asking for help :) ), specially considering that I already have a working LDAP working with several hundreds users relying on them to do their work, so it's not possible to me to start from scratch, I have to use what I already have (and not break anything in the process).

For the reason above, I can't compile OpenLDAP myself (I have to use what is already there).