There isn't a quick and easy way of doing this, but if you are semi-familiar with XML, I would be tempted to do this doing a backup of the course, and editing the moodle.xml page.
Create a Choice in the 1st week of your course, then do a full backup of your course and save it seperately just in case you break something! then create a backup file with only the data you want - eg don't backup the user data and only include the choice module.
- open a new copy of the moodle.xml file created inside the backup zip file.
now follow the instructions in the attached file to this post - I couldn't get moodle to display the XML tags properly, so put these in a seperate file!
after making the changes given in the attached file., restore the file - I would suggest to a new course first to make sure you didn't break anything! and then if that works restore it to your own course "adding data to it" - (you will end up with 2 choices in the first section, but you can just delete one of them!)
*edit* - removed xml tags from post and placed the instrutions in attatched text file.