Custom Wordpress PHP script

Hi, We have a Wordpress directory and for the listings to show on the front-end, the address must be validated in the backend. Usually, you would type address and then, you select relevant address from dropdown populated by google. We have the address in a custom field, listing_map_location_address. We need someone to create a script, that copies the address from the custom field into the Map Location field and then selects the first address from Google dropdown that populates. here are the address samples: Melbourne, VIC, 3000, Australia Pyrmont, NSW, 2009, Australia Red Hill, ACT, 2603, Australia Sydney, NSW, 2000, Australia Surry Hills, NSW, 2010, Australia Paddington, QLD, 4064, Australia Mildura, VIC, 3500, Australia East Launceston, TAS, 7250, Australia Proserpine, QLD, 4800, Australia Casula, NSW, 2170, Australia Need this done urgently