Unfortunately there's nothing built in to do that.
Probably simplest way would be to create a powershell script that runs daily and reads the last password change date from the database, sending an email telling the user to change their password. It wouldn't FORCE the change though (though they'd get daily
emails until they changed it).
The real way would be to either customize the login page, or create some code that runs on every page, that redirects the user to the change password page if their password hasn't been changed in 90 days.