OpenLDAP Transparrent Overlay to Azure ADDS

Question

Currently we have a OpenLDAP setup with a translucent overlay to our on-site Active Directory servers. (This is inherited and we did not set it up nor do we have any deep knowledge of how this is set up).
We are migrating to a new domain hosted in Azure ADDS and need to replicate this environment, but have no real ideas on where to start or if it is possible.

Does anyone know if this is possible, and if so any tutorials on it? I have looked high and low and have come up empty.

Thank you!