OpenLDAP: slapi & contrib overlays

Hi, I'm building OpenLDAP 2.4.39 from source under MinGW. A couple of questions: a) I added '--enable-slapi' to configure. I got a few compilation errors. Is slapi Windows ready? b) I added some contrib modules (e.g. allop, lastbind, etc) and tried to link them statically. Compilation and linking worked OK. Then, I type: slapd -VVV and I expect to see those contrib modules listed under the overlay section. None of them appear. I added 'overlay allop' to slapd.conf, but when slapd starts, I get: 5314932d overlay "allop" not found 5314932d ..\etc\openldap\slapd.conf: line 30: <overlay> handler exited with 1! Can anyone point me to the right direction? Thanks in advance. Ciao, Sergio.