For endowments (awqaf) and related duties, a Muslim should be employed to a possible extent. If there is no Muslim available, it is lawful to employ a non-Muslim in compulsion.
[Islamopedia Online Explanatory Note: The answer references Volume 2 page 408 of Fatawa al-Hindiyah which states: "Do not make being a Muslim or a freeman a provision when in compulsion..." The referenced book, al-Fatawa al-Hindiyah, is a book of fatwas from the late Indian Middle Ages which is a well-known reference in Hanafi jurispudence and was produced by a group of scholars under the direction of the Mughal emperor Aurangzeb (d. 1707). The scholars of this book were al-Shaykh Nizam, al-Hasan ibn Mansur al-Uzjandi al-Farghani Qadi Khan, and Ibn al-Bazzaz Kardari. See URL for Urdu text.]