Excel tips: How to populate cells after locking other cells

We're doing a college football pick 'em here at work. the set up we have now is i email the spreadsheet out with the picks and the spreads for each game and through out the week, they resend the spreadsheet with their picks. this can get time consuming.

My idea is to put the spreadsheet on a server to where all the players can access it and put their own picks into the spread sheet and save it. However, that can cause chaos due to them being able to see other peoples picks before their own. so, i was going to assign passwords to each column/player that i would be the owner of. once they enter their picks, they would proceed to lock their picks, and the other cells/picks from the other players would automatically show. and if they wanted to change their picks, they couldn't cause they wouldn't know the password to their column.