Getting Manager DN from AD to Okta

We have requirement for Okta to AD provisioning, and at the time of user creation, update we have to set “Manager” attribute value on AD side as full manager (User) DN value. From Workday ( HR source for Okta) , we are getting Manager username which we can resolve in Okta, however we are not able to set full DN value on AD provisioning. How can we achieve this, is it possible through expression language or by any other means (workflow).? Please let us know if you have any insight/inputs on this