Connect wall access point to a modem or router

Is it possible to set up a wireless connection between a router or modem to a wall mount access point? We have an access point, we cannot use, because it does not support an ethernet connection. Can we possibly get a second modem or router wihich supports a wireless connection, or bridge connections to the access point. We cannot get information on the access points internal settings, as it belongs to an isp. We live in a rental, in rural Mexico, so there are few internet options The acesss point was installed when our unilts were built However, We need the router to use a vpn.

Any help appreciated
Thanks