as long as your computers are set up, you can access his db remotely, just do:
mysql_connect("nsWhatever.thatserver.com","username", "password");
he'll need to give you permission:
GRANT [privileges] on targetDb.* to username@'%' identified by 'reeelysecret'
and you should be able to connect.
You may find a bit of latency which may or may not be tolerable.
Sam