Auto fill web form from excel

Our organization does a lot of airline ticket purchasing. We usually have flexibility with the dates we purchase tickets and even the airports. I want to put all of the possible itinerary dates and airports into Excel and then have each itinerary process on a search engine with the airline and return what the fare is for each itinerary. Each row would contain the following data: departure date, return date, departure airport, return airport. I would like to fill the excel spreadsheet with that data on each row and have the excel sheet submit each row to the airline search form, submit, get the fare, and then enter it into the spreadsheet along with a date of when the search was conducted. Some of the sites I want to do this at require a login and password before allowing a search.