Transparent proxy to existing LDAP but with replacing specific attribute from another source

Hi.

A have Active Directory domain across 30+ domain controllers.

In one single location, I have a server with corporate software that uses AD as normal ordinary LDAP with simple binds and it takes users.

I want to add users their high quality photos, but I don't want them across all domain controllers in active directory.

Can I build a proxy server with OpenLDAP that will proxy all requests to backend AD servers and return results, but for results it will replace one attribute, jpegPhoto, if it was requested, with some binary contents taken from elsewhere ?