Hi Joanna,
Firstly, you will need to contact the company with whom you booked your package holiday to request your US confirmation number. (The last US confirmation number which I received was an eight digit reference which was made up of three letters followed by five numerical digits.)
Once you have received this information, here is what you need to do:-
1/ Log into the Walt Disney World website and then click on the 'Select an International Version' box at the bottom of the Walt Disney World website and select USA: English.
2/ Click on where it says "My Disney Vacation" next to a little yellow suitcase at the top of the home page
3/ Click on "My Reservations" on the right hand side of the page
4/ Click on "Retrieve Reservations" on the right hand side of the page
5/ Select "Package/Room Reservation, and where it asks "How did you book your stay?" select "Through a Travel Professional" and enter your eight digit US confirmation number.
This should then bring up your Package/Room Reservation.
Now you can proceed to the Make Dining Reservations page of the Walt Disney World website.
You should notice at the bottom of the 'Make a Reservation' box, that it says "I want to use my dining plan to book reservations" If you click on this link you will be asked to confirm your Walt Disney World reservation. Once you have entered your confirmation number, last name and arrival date, you should be able to make Advance Dining Reservations for the first 10 days of your trip at 180 days prior to your visit rather than having to make them one day at a time.
If you do experience any difficulties, I would recommend that you call and speak to a Cast Member at Dining Reservations on 001 407 939 3463 who will be happy to assist you.
Wishing you a magical holiday filled with memories which will last a lifetime!