Find Email Address from a list of companies

I have a list of some 800 company names that I wish to obtain an email address from (if it exists) - the task is by google UK website to enter the company name and from the results achieved in the search engine copy and paste the email address details to an excel spreadsheet and then forward that to me. I need the data back mid week so its quite presssing I estimate it will take no longer than 3 working days to complete